Stéphane Luchini

Chercheur ,  CNRS

Économie publique
Statut
Chargé de recherche
Domaine(s) de recherche
Économie comportementale et expérimentale, Économétrie, Économie de l'environnement
Thèse
2000, Aix-Marseille Université
Contact
stephane.luchini[at]univ-amu.fr
+33(0)4 13 55 25 58
Adresse

AMU - AMSE
5-9 Boulevard Maurice Bourdet, CS 50498
​13205 Marseille Cedex 1

Résumé This paper tests experimentally how preferences for redistribution of members of the general public depend on how money is earned. An experiment was designed to form of “microparticipatory-democracy”where redistribution from winners to losers is decided through a sequential strategy-proof majority voting procedure. Based on five distributive justice theories, we elicit people’s preferences for redistribution when their earnings come from four factors: effort, social circumstances, brute luck, and option luck. In the aggregate, our results show that a relative majority of people agree with Dworkin’s cut, namely, to compensate for social circumstances and brute luck but not effort and option luck. Participants with bad outcomes are more likely to engage in a self-serving vote, but on average, the dominant concern in voting remains people’s fairness view. The knowledge of the distribution of earnings and petition for equality of opportunity make participants vote more in favor of redistribution.
Mots clés Experiment, Responsibility, Equality of opportunity, Micro participatory-democracy, Social justice
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Résumé There is a significant gap in turnout between young people and older voters. The failure to instill a voting habit at an early age may have long term consequences in terms of future political participation as well as on other civic behaviors. Using a pre-registered online experiment with 3790 subjects, we implemented behavioral interventions aiming to stimulate youth turnout in the 2022 French presidential election. We rely on an innovative incentive scheme to measure their consequences on (self-reported) actual voting behavior. We also provide evidence on the effect of one behavioral intervention on youth turnout in a less salient election, the French legislative election that took place two months after the Presidential one. The results from the two experiments show the absence of any differences in turnout between the baseline and the treatment conditions. We investigate several mechanisms that can explain our results.
Mots clés Youth turnout, Behavioral nudges, Field experiment, Behavioral public policy
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Résumé Most studies assessing animal decision-making under risk rely on probabilities that are typically larger than 10%. To study Decision-Making in uncertain conditions, we explore a novel experimental and modelling approach that aims at measuring the extent to which rats are sensitive - and how they respond - to outcomes that are both rare (probabilities smaller than 1%) and extreme in their consequences (deviations larger than 10 times the standard error). In a four-armed bandit task, stochastic gains (sugar pellets) and losses (time-out punishments) are such that extremely large - but rare - outcomes materialize or not depending on the chosen options. All rats feature both limited diversification, mixing two options out of four, and sensitivity to rare and extreme outcomes despite their infrequent occurrence, by combining options with avoidance of extreme losses (Black Swans) and exposure to extreme gains (Jackpots). Notably, this sensitivity turns out to be one-sided for the main phenotype in our sample: it features a quasi-complete avoidance of Black Swans, so as to escape extreme losses almost completely, which contrasts with an exposure to Jackpots that is partial only. The flip side of observed choices is that they entail smaller gains and larger losses in the frequent domain compared to alternatives. We have introduced sensitivity to Black Swans and Jackpots in a new class of augmented Reinforcement Learning models and we have estimated their parameters using observed choices and outcomes for each rat. Adding such specific sensitivity results in a good fit of the selected model - and simulated behaviors that are close - to behavioral observations, whereas a standard Q-Learning model without sensitivity is rejected for almost all rats. This model reproducing the main phenotype suggests that frequent outcomes are treated separately from rare and extreme ones through different weights in Decision-Making.
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Résumé We provide a novel way to correct the effective reproduction number for the time-varying amount of tests, using the acceleration index (Baunez et al., 2021) as a simple measure of viral spread dynamics. Not correcting results in the reproduction number being a biased estimate of viral acceleration and we provide a formal decomposition of the resulting bias, involving the useful notions of test and infectivity intensities. When applied to French data for the COVID-19 pandemic (May 13, 2020-October 26, 2022), our decomposition shows that the reproduction number, when considered alone, characteristically underestimates the resurgence of the pandemic, compared to the acceleration index which accounts for the time-varying volume of tests. Because the acceleration index aggregates all relevant information and captures in real time the sizable time variation featured by viral circulation, it is a more parsimonious indicator to track the dynamics of an infectious disease outbreak in real time, compared to the equivalent alternative which would combine the reproduction number with the test and infectivity intensities.
Mots clés Virus testing, Pandemics, COVID 19, Public and occupational health, France, Acceleration, Diagnostic medicine, Public policy
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Résumé BACKGROUND: Meta-analyses have shown that preexisting mental disorders may increase serious Coronavirus Disease 2019 (COVID-19) outcomes, especially mortality. However, most studies were conducted during the first months of the pandemic, were inconclusive for several categories of mental disorders, and not fully controlled for potential confounders. Our study objectives were to assess independent associations between various categories of mental disorders and COVID-19-related mortality in a nationwide sample of COVID-19 inpatients discharged over 18 months and the potential role of salvage therapy triage to explain these associations. METHODS AND FINDINGS: We analysed a nationwide retrospective cohort of all adult inpatients discharged with symptomatic COVID-19 between February 24, 2020 and August 28, 2021 in mainland France. The primary exposure was preexisting mental disorders assessed from all discharge information recorded over the last 9 years (dementia, depression, anxiety disorders, schizophrenia, alcohol use disorders, opioid use disorders, Down syndrome, other learning disabilities, and other disorder requiring psychiatric ward admission). The main outcomes were all-cause mortality and access to salvage therapy (intensive-care unit admission or life-saving respiratory support) assessed at 120 days after recorded COVID-19 diagnosis at hospital. Independent associations were analysed in multivariate logistic models. Of 465,750 inpatients with symptomatic COVID-19, 153,870 (33.0%) were recorded with a history of mental disorders. Almost all categories of mental disorders were independently associated with higher mortality risks (except opioid use disorders) and lower salvage therapy rates (except opioid use disorders and Down syndrome). After taking into account the mortality risk predicted at baseline from patient vulnerability (including older age and severe somatic comorbidities), excess mortality risks due to caseload surges in hospitals were +5.0% (95% confidence interval (CI), 4.7 to 5.2) in patients without mental disorders (for a predicted risk of 13.3% [95% CI, 13.2 to 13.4] at baseline) and significantly higher in patients with mental disorders (+9.3% [95% CI, 8.9 to 9.8] for a predicted risk of 21.2% [95% CI, 21.0 to 21.4] at baseline). In contrast, salvage therapy rates were significantly higher than expected in patients without mental disorders (+4.2% [95% CI, 3.8 to 4.5]) and lower in patients with mental disorders (-4.1% [95% CI, -4.4; -3.7]). The main limitations of our study point to the assessment of COVID-19-related mortality at 120 days and potential coding bias of medical information recorded in hospital claims data, although the main study findings were consistently reproduced in multiple sensitivity analyses. CONCLUSIONS: COVID-19 patients with mental disorders had lower odds of accessing salvage therapy, suggesting that life-saving measures at French hospitals were disproportionately denied to patients with mental disorders in this exceptional context.
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Résumé Public good games are at the core of many environmental challenges. In such social dilemmas, a large share of people endorse the norm of reciprocity. A growing literature complements this finding with the observation that many players exhibit a self-serving bias in reciprocation: "weak reciprocators" increase their contributions as a function of the effort level of the other players, but less than proportionally. In this paper, we build upon a growing literature on truth-telling to argue that weak reciprocity might be best conceived not as a preference, but rather as a symptom of an internal trade-off at the player level between (i) the truthful revelation of their private reciprocal preference, and (ii) the economic incentives they face (which foster free-riding). In truth-telling experiments, many players misrepresent private information when this is to their material benefit, but to a significantly lesser extent than what would be expected based on the profit-maximizing strategy. We apply this behavioral insight to strategic situations, and test whether the preference revelation properties of the classic voluntary contribution game can be improved by offering players the possibility to sign a classic truth-telling oath. Our results suggest that the honesty oath helps increase cooperation (by 33% in our experiment). Subjects under oath contribute in a way which is more consistent with (i) the contribution they expect from the other players and (ii) their normative views about the right contribution level. As a result, the distribution of social types elicited under oath differs from the one observed in the baseline: some free-riders, and many weak reciprocators, now behave as pure reciprocators.
Mots clés Social preferences, Reciprocity, Public goods, Cooperation, Truth-telling oath, Social preferences
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Résumé It can be assumed that higher SARS-CoV-2 infection risk is associated with higher COVID-19 vaccination intentions, although evidence is scarce. In this large and representative survey of 6007 adults aged 18–64 years and residing in France, 8.1% (95% CI, 7.5–8.8) reported a prior SARS-CoV-2 infection in December 2020, with regional variations according to an East–West gradient (p < 0.0001). In participants without prior SARS-CoV-2 infection, COVID-19 vaccine hesitancy was substantial, including 41.3% (95% CI, 39.8–42.8) outright refusal of COVID-19 vaccination. Taking into account five characteristics of the first approved vaccines (efficacy, duration of immunity, safety, country of the vaccine manufacturer, and place of administration) as well as the initial setting of the mass vaccination campaign in France, COVID-19 vaccine acceptance would reach 43.6% (95% CI, 43.0–44.1) at best among working-age adults without prior SARS-CoV-2 infection. COVID-19 vaccine acceptance was primarily driven by vaccine characteristics, sociodemographic and attitudinal factors. Considering the region of residency as a proxy of the likelihood of getting infected, our study findings do not support the assumption that SARS-CoV-2 infection risk is associated with COVID-19 vaccine acceptance.
Mots clés SARS-CoV-2, COVID-19, Mass vaccination, Anti-vaccination behavior, Vaccine hesitancy, Survey experiment, Discrete choice experiment, France
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Résumé Comment mesurer le plus finement possible l'accélération ou la décélération d'une épidémie ?
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Résumé Does giving taxpayers a voice over the destination of tax revenues lead to more honest income declarations? Previous experiments have shown that giving participants the opportunity to select the organization that receives their tax funds tends to increase tax compliance. The aim of this paper is to assess whether this increase in compliance is induced by the sole fact of giving subjects a choice—a “direct democracy effect”. To that aim, we ask participants to a tax evasion game to choose, in a collective or individual choice setting, between two very similar organizations which provide the same social (ecological) benefits. We elicit compliance for both organizations before the choice is made so as to control for the counter-factual compliance decision. We find that democracy does not increase compliance, and even observe a slight negative effect—in particular for women. Our results confirm the existence of a commitment effect of democracy, leading to favor more the selected organization when it was actively chosen. The commitment effect of democracy is however not enough to overcome the decrease in the level of compliance. Thanks to response times data, we show that prior choice on similar options as compared to a purely random selection weakens the preference for honesty. One important field application of our results is that democracy in tax spending must offer real choices to tax payers to improve compliance.
Mots clés Commitment, Direct democracy effect, Voting, Tax evasion game
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Résumé In a competitive business environment, dishonesty can pay. Self-interested executives and managers can have incentive to shade the truth for personal gain. In response, the business community has considered how to commit these executives and managers to a higher ethical standard. The MBA Oath and the Dutch Bankers Oath are examples of such a commitment device. The question we test herein is whether the oath can be used as an effective form of ethics management for future executives/managers-who for our experiment we recruited from a leading French business school-by actually improving their honesty. Using a classic Sender-Receiver strategic game experiment, we reinforce professional identity by pre-selecting the group to which Receivers belong. This allows us to determine whether taking the oath deters lying among future managers. Our results suggest "yes and no." We observe that these future executives/managers who took a solemn honesty oath as a Sender were (a) significantly more likely to tell the truth when the lie was detrimental to the Receiver, but (b) were not more likely to tell the truth when the lie was mutually beneficial to both the Sender and Receiver. A joint product of our design is our ability to measure in-group bias in lying behavior in our population of subjects (comparing behavior of subjects in the same and different business schools). The experiment provides clear evidence of a lack of such bias.
Mots clés Commitment, Lying, In-group bias
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Résumé An acceleration index is proposed as a novel indicator to track the dynamics of COVID-19 in real-time. Using data on cases and tests in France for the period between the first and second lock-downs-May 13 to October 25, 2020-our acceleration index shows that the pandemic resurgence can be dated to begin around July 7. It uncovers that the pandemic acceleration was stronger than national average for the [59-68] and especially the 69 and older age groups since early September, the latter being associated with the strongest acceleration index, as of October 25. In contrast, acceleration among the [19-28] age group was the lowest and is about half that of the [69-78]. In addition, we propose an algorithm to allocate tests among French "dé partements" (roughly counties), based on both the acceleration index and the feedback effect of testing. Our acceleration-based allocation differs from the actual distribution over French territories, which is population-based. We argue that both our acceleration index and our allocation algorithm are useful tools to guide public health policies as France might possibly enter a third lock-down period with indeterminate duration.
Mots clés France, Sub-national allocation of tests, Real-time Analysis, Acceleration Index, Indicator of epidemic dynamics, COVID-19
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Résumé BACKGROUND: Opinion polls on vaccination intentions suggest that COVID-19 vaccine hesitancy is increasing worldwide; however, the usefulness of opinion polls to prepare mass vaccination campaigns for specific new vaccines and to estimate acceptance in a country's population is limited. We therefore aimed to assess the effects of vaccine characteristics, information on herd immunity, and general practitioner (GP) recommendation on vaccine hesitancy in a representative working-age population in France. METHODS: In this survey experiment, adults aged 18-64 years residing in France, with no history of SARS-CoV-2 infection, were randomly selected from an online survey research panel in July, 2020, stratified by gender, age, education, household size, and region and area of residence to be representative of the French population. Participants completed an online questionnaire on their background and vaccination behaviour-related variables (including past vaccine compliance, risk factors for severe COVID-19, and COVID-19 perceptions and experience), and were then randomly assigned according to a full factorial design to one of three groups to receive differing information on herd immunity (>50% of adults aged 18-64 years must be immunised [either by vaccination or infection]; >50% of adults must be immunised [either by vaccination or infection]; or no information on herd immunity) and to one of two groups regarding GP recommendation of vaccination (GP recommends vaccination or expresses no opinion). Participants then completed a series of eight discrete choice tasks designed to assess vaccine acceptance or refusal based on hypothetical vaccine characteristics (efficacy [50%, 80%, 90%, or 100%], risk of serious side-effects [1 in 10 000 or 1 in 100 000], location of manufacture [EU, USA, or China], and place of administration [GP practice, local pharmacy, or mass vaccination centre]). Responses were analysed with a two-part model to disentangle outright vaccine refusal (irrespective of vaccine characteristics, defined as opting for no vaccination in all eight tasks) from vaccine hesitancy (acceptance depending on vaccine characteristics). FINDINGS: Survey responses were collected from 1942 working-age adults, of whom 560 (28·8%) opted for no vaccination in all eight tasks (outright vaccine refusal) and 1382 (71·2%) did not. In our model, outright vaccine refusal and vaccine hesitancy were both significantly associated with female gender, age (with an inverted U-shaped relationship), lower educational level, poor compliance with recommended vaccinations in the past, and no report of specified chronic conditions (ie, no hypertension [for vaccine hesitancy] or no chronic conditions other than hypertension [for outright vaccine refusal]). Outright vaccine refusal was also associated with a lower perceived severity of COVID-19, whereas vaccine hesitancy was lower when herd immunity benefits were communicated and in working versus non-working individuals, and those with experience of COVID-19 (had symptoms or knew someone with COVID-19). For a mass vaccination campaign involving mass vaccination centres and communication of herd immunity benefits, our model predicted outright vaccine refusal in 29·4% (95% CI 28·6-30·2) of the French working-age population. Predicted hesitancy was highest for vaccines manufactured in China with 50% efficacy and a 1 in 10 000 risk of serious side-effects (vaccine acceptance 27·4% [26·8-28·0]), and lowest for a vaccine manufactured in the EU with 90% efficacy and a 1 in 100 000 risk of serious side-effects (vaccine acceptance 61·3% [60·5-62·1]). INTERPRETATION: COVID-19 vaccine acceptance depends on the characteristics of new vaccines and the national vaccination strategy, among various other factors, in the working-age population in France. FUNDING: French Public Health Agency (Santé Publique France).
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Résumé We propose a structural econometric model that incorporates altruism towards other household members into the willingness to pay for a public good. The model distinguishes preferences for public good improvements for oneself from preferences for improvements for other household members. We test for three different types of altruism - ‘pure self-interest’, ‘pure altruism’ and ‘public-good-focused non-pure altruism’. Using French contingent valuation data regarding air quality improvements, we find positive and significant degrees of concern for children under the age of 18, which are explained by determinants related to health and subjective air quality assessment. All other forms of pure or air-quality-focused altruism within the family are insignificant, including for children over 18, siblings, spouses, and parents. This result suggests that benefit estimates that do not consider altruism could undervalue improvements in air quality in France.
Mots clés Willingness to pay, Contingent valuation, Field experiment, Familial altruism, Air pollution
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Résumé This study explores whether an oath to honesty can reduce both shirking and lying among crowd-sourced internet workers. Using a classic coin-flip experiment, we first confirm that a substantial majority of Mechanical Turk workers both shirk and lie when reporting the number of heads flipped. We then demonstrate that lying can be reduced by first asking each worker to swear voluntarily on his or her honor to tell the truth in subsequent economic decisions. Even in this online, purely anonymous environment, the oath significantly reduced the percent of subjects telling “big” lies (by roughly 27%), but did not affect shirking. We also explore whether a truth-telling oath can be used as a screening device if implemented after decisions have been made. Conditional on flipping response, MTurk shirkers and workers who lied were significantly less likely to agree to an ex-post honesty oath. Our results suggest oaths may help elicit more truthful behavior, even in online crowd-sourced environments
Mots clés Experimental economics, Honesty, Solemn Oath, Mechanical Turk, Lying, Shirking
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Résumé La recherche en sciences humaines et sociales (SHS), à qui l’on pose régulièrement la question de son « utilité », a été massivement mobilisée dans la première partie de l’année 2020, tant par les médias et les institutions. Elle s’est montrée d’une grande réactivité, en adaptant ses calendriers et ses objectifs, en modifiant ses formats d’interventions (wébinaires, cours en distanciel). Chercheuses et chercheurs, enseignant(e)s-chercheurs ont été présents, et ce malgré des inégalités générées par le confinement dans le travail de recherche, notamment en termes de genre. Le présent travail a pour ambition de proposer à son lecteur une analyse mobilisant les travaux des SHS dans leur ensemble. Sans prétendre à l’exhaustivité, il tisse les fils, à travers les questions qu’il aborde, d’une discipline à une autre, composant un ensemble dans lequel les SHS entrent en résonance les unes avec les autres, déploient leur complémentarité, et créent une analyse commune, qu’elles relèvent plutôt des sciences sociales ou des humanités. Il a pour objectif de rendre manifeste un capital scientifique des SHS en tant que telles, pour aborder les différents questionnements que suscite la pandémie de Covid-19. La recherche actuelle en SHS sur la pandémie, sa gestion politique, et ses enjeux, ne s’élabore pas ex nihilo. Tout en prenant la mesure de la spécificité des temps présents, elle s’appuie sur un ensemble de cadres théoriques, de méthodes, d’analyses élaborés dans d’autres contextes, remobilisés, réactualisés, enrichis à la lumière des problématiques associées à la pandémie de Covid 19. Par ailleurs, le parti-pris de ce travail a été de tenir compte d’emblée de la dimension mondiale de la pandémie, et de ne pas s’en tenir à la situation française. Ainsi, plusieurs contextes nationaux, voire continentaux sont explorés sur tel ou tel point et la dimension mondiale de la pandémie y est prise en compte en tant que telle. Enfin, ce document s’intéresse aussi à la manière même dont les sciences humaines et sociales se sont mobilisées, en France, dans le contexte de la pandémie de Covid 19, aux formes collaboratives, aux pratiques pluridisciplinaires particulièrement adoptées face à cette pandémie. Il se structure en cinq parties : la première porte sur la manière dont les SHS font de la crise une question et un objet de connaissance (A – Du cadrage de la crise dans l’espace public à la crise comme objet de connaissance - l’exemple de la France). La seconde aborde un point saillant des analyses élaborées au cours des derniers mois, qui envisagent la pandémie comme un révélateur, voire un amplificateur d’enjeux pré-existants (B). Puis, la troisième partie s’intéresse aux sociétés et aux gouvernements confrontés à la pandémie (C), autrement dit aux formes de la gestion de la crise par le pouvoir politique, à la mobilisation des sciences et à l’exercice du pouvoir, ainsi qu’aux mesures prises et aux attitudes des populations au regard de ces mesures. La quatrième partie présente la façon dont le temps de la pandémie a été traversé de questionnements pour le futur, questionnements qui à leur tour impriment des orientations pour la recherche en SHS (D. Se réinventer en temps de pandémie). Enfin, la cinquième et dernière partie invite le lecteur à découvrir comment les SHS se sont mobilisées en temps de pandémie, comment elles ont collaboré et entrepris de documenter à chaud la crise sanitaire tout en acceptant de voir se renouveler questions, objets, méthodes sous l’effet de cette crise (E. Quand la crise invite aux collaborations et à une réflexion sur le « transfert » des connaissances).
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Résumé Tests are crucial to know about the number of people who have fallen ill with COVID-19 and to understand in real-time whether the dynamics of the pandemic is accelerating or decelerating. But tests are a scarce resource in many countries. The key but still open question is thus how to allocate tests across sub-national levels. We provide a data-driven and operational criterion to allocate tests efficiently across regions or provinces, with the view to maximize detection of people who have been infected. We apply our criterion to Italian regions and compute the shares of tests that should go to each region, which are shown to differ significantly from the actual distribution.
Mots clés COVID-19, Italy, Acceleration of harm, Deceleration of harm, Epidemic dynamics, Efficiency criterion, Sub-national allocation of tests, Real-time Analysis
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Résumé Using two earned income/tax declaration experimental designs we show that only partial liars are affected by a truth-telling oath, a non-price commitment device. Under oath, we see no change in the number of chronic liars and fewer partial liars. Rather than smoothly increasing their compliance, we also observe that partial liars who respond to the oath, respond by becoming fully honest under oath. Based on both response times data and the consistency of subjects when several compliance decisions are made in a row, we show that partial lying arises as the result of weak preferences towards profitable honesty. The oath only transforms people with weak preferences for lying into being committed to the truth.
Mots clés Tax evasion, Commitment, Oath, Honesty, Part-time Lying
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Résumé L’évasion fiscale est un sujet qui se dérobe aux outils de l’analyse économique traditionnelle. D’une part, comme toute activité illégale, l’évasion fiscale échappe à l’observation du chercheur en même temps qu’elle se dissimule aux autorités : l’analyse empirique de son ampleur, de ses déterminants et de la manière dont différents dispositifs l’affectent est nécessairement très limitée. D’autre part, sur le plan théorique, l’application simple du calcul coût-bénéfice auquel est supposé se livrer le contribuable « rationnel » conduit à un paradoxe : contrairement à une idée largement répandue, les bénéfices de l’évasion fiscale sont tellement élevés, et le risque de sanction est tellement faible, que l’on peut s’étonner qu’elle soit aussi peu pratiquée dans l’ensemble des économies développées. Plutôt que l’évasion fiscale, c’est donc la « soumission fiscale » qui en constitue le pendant, la disposition à payer l’impôt, qu’il convient d’expliquer pour en comprendre les déterminants. Le double défi que posent les décisions d’évasion fiscale à l’analyse économique n’a pu être relevé que très récemment, grâce à l’émergence, au cours des vingt dernières années, d’une nouvelle approche, l’économie comportementale, qui s’appuie sur la psychologie pour mieux comprendre les comportements économiques ; et, conjointement, d’une nouvelle méthode, l’économie expérimentale, qui permet d’étudier empiriquement les comportements économiques sur lesquels il est difficile de collecter des données convaincantes. Cet opuscule rend compte des résultats de ces travaux et présente un panorama des outils de politique fiscale qui s’en dégagent.
Mots clés Economie politique, Aspect psychologique, Lutte contre, Fraude fiscale
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Résumé This chapter presents an intuitive overview of the methods that researchers can use to estimate the monetary value of changes in health outcomes. These methods are separated into two categories: stated preference methods and revealed preference methods. Stated preference methods ask people how much they are willing to pay for health improvements directly using surveys of the relevant population. Revealed preference methods infer the trade-offs that people make between health and money indirectly by observing everyday behavior, such as when people accept a riskier job in return for higher wages; or when they buy products to protect their health from hazards. The chapter discusses the main advantages and disadvantages of each method.
Mots clés Choice experiments, Contingent valuation, Stated preference methods, Hedonic regression, Value of a statistical life
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Résumé Objectives: To evaluate the clinical and economic burden of head and neck squamous cell carcinoma (HNSCC) in France. Methods: All 53,255 incident adult patients discharged with a first diagnosis of HNSCC in 2010–2012 were identified from the 2008–2013 French National Hospital Discharge (PMSI) database. We conducted a retrospective longitudinal analysis of prognosis and direct costs attributable to HNSCC. Results: Direct medical costs attributable to HNSCC care amounted to 665 million euros in 2012 in France. The majority (62%) of incident patients were 64 years old or less at HNSCC diagnosis and incurred 1.3-fold higher mean direct costs as compared to elderly patients (41,909 vs 32,221 euros over 3 years, respectively; p
Mots clés Burden of disease, Costs, Prognosis, Head and neck squamous cell carcinoma, National Hospital discharge database
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Résumé Background : Health state utility (HSU) is a core component of QALYs and cost-effectiveness analysis, although HSU is rarely estimated among a representative sample of patients. We explored the feasibility of assessing HSU in head and neck cancer from the French National Hospital Discharge database. Methods: An exhaustive sample of 53,258 incident adult patients with a first diagnosis of head and neck cancer was identified in 2010–2012. We used a cross-sectional approach to define five health states over two periods: three "cancer stages at initial treatment" (early, locally advanced or metastatic stage); a "relapse state" and otherwise a "relapse-free state" in the follow-up of patients initially treated at early or locally advanced stage. In patients admitted in post-acute care, a two-parameter graded response model (Item Response Theory) was estimated from all 144,012 records of six Activities of Daily Living (ADLs) and the latent health state scale underlying ADLs was calibrated with the French EQ-5D-3 L social value set. Following linear interpolation between all assessments of the patient, daily estimates of utility in post-acute care were averaged by health state, patient and month of follow-up. Finally, HSU was estimated by health state and month of follow-up for the whole patient population after controlling for survivorship and selection in post-acute care. Results: Head and neck cancer was generally associated with poor HSU estimates in a real-life setting. As compared to “distant metastasis at initial treatment”, mean HSU was higher in other health states, although numerical differences were small (0.45 versus around 0.54). It was primarily explained by the negative effects on HSU of an older age (38.4% aged ≥70 years in “early stage at initial treatment”) and comorbidities (> 50% in other health states). HSU estimates significantly improved over time in the “relapse-free state” (from 8 to 12 months of follow-up). Conclusions: HSU estimates in head and neck cancer were primarily driven by age at diagnosis, comorbidities, and time to assessment of cancer survivors. This feasibility study highlights the potential of estimating HSU within and across severe conditions in a systematic way at the national level.
Mots clés Head and neck cancer, Health state utility, EQ-5D-3L, QALYs, Cost-effectiveness analysis, Activities of daily living, Item response theory, National Hospital discharge database
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Résumé Why do people pay taxes? Rational choice theory has fallen short in answering this question. Another explanation, called “tax morale”, has been promoted. Tax morale captures the behavioral idea that non-monetary preferences (like norm-submission, moral emotions and moral judgments) might be better determinants of tax compliance than monetary trade-offs. Herein we report on two lab experiments designed to assess whether norm-submission, moral emotions (e.g. affective empathy, cognitive empathy, propensity to feel guilt and shame) or moral judgments (e.g. ethics principles, integrity, and moralization of everyday life) can help explain compliance behavior. Although we find statistically significant correlations of tax compliance behavior with empathy and shame, the economic significance of these correlations are low–—more than 80% of the variability in compliance remains unexplained. These results suggest that tax authorities should focus on the institutional context, rather than individual preference characteristics, to handle tax evasion.
Mots clés Tax evasion, Tax morale, Morality, Personality traits, Psychometrics
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Résumé Oath-taking for senior executives has been promoted as a mean to enhance honesty within and towards organizations. Herein we explore whether people who voluntarily sign a solemn truth-telling oath are more committed to sincere behavior when offered the chance to lie. We design an experiment to test how the oath affects truth-telling in two contexts: a neutral context replicating the typical experiment in the literature, and a "loaded" context in which we remind subjects that "a lie is a lie." We consider four payoff configurations, with differential monetary incentives to lie, implemented as within-subjects treatment variables. The results are reinforced by robustness investigations in which each subject made only one lying decision. Our results show that the oath reduces lying, especially in the loaded environment-falsehoods are reduced by fifty percent. The oath, however, have a weaker effect on lying in the neutral environment. The oath did affect decision times in all instances: the average person takes significantly more time deciding whether to lie under oath.
Mots clés Lies, Deception, Laboratory Experiment, Truth-telling oath
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Résumé Stated preference surveys are usually carried out in one session, without any follow-up interview after respondents have had the opportunity to experience the public goods or policies they were asked to value. Consequently, a stated preference survey needs to be designed so as to provide respondents with all the relevant information, and to help them process this information so they can perform the valuation exercise properly. In this paper, we study experimentally an elicitation procedure in which respondents are provided with a sequence of different types of information (social cues and objective information) that allows them to sequentially revise their willingness-to-pay (WTP) values. Our experiment was carried out in large groups using an electronic voting system which allows us to construct social cues in real time. To analyse the data, we developed an anchoring-type structural model that allows us to estimate the direct effect (at the current round) and the indirect effect (on subsequent rounds) of information. Our results shed new light on the interacted effect of social cues and objective information: social cues have little or no direct effect on WTP values but they have a strong indirect effect on how respondents process scientific information. Social cues have the most noticeable effect on respondents who initially report a WTP below the group average but only after receiving additional objective information about the valuation task. We suggest that the construction and the provision of social cues should be added to the list of tools and controls for stated preference methods.
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Résumé This article presents an assessment of individual uncertainty about longevity. A survey performed on 3,331 French people enables us to record several survival probabilities per individual. On this basis, we compute subjective life expectancies (SLE) and subjective uncertainty regarding longevity (SUL), the standard deviation of each individual’s subjective distribution of her or his own longevity. It is large and equal to more than 10 years for men and women. Its magnitude is comparable to the variability of longevity observed in life tables for individuals under 60, but it is smaller for those older than 60, which suggests use of private information by older respondents. Our econometric analysis confirms that individuals use private information—mainly their parents’ survival and longevity—to adjust their level of uncertainty. Finally, we find that SUL has a sizable impact, in addition to SLE, on risky behaviors: more uncertainty on longevity significantly decreases the probability of unhealthy lifestyles. Given that individual uncertainty about longevity affects prevention behavior, retirement decisions, and demand for long-term care insurance, these results have important implications for public policy concerning health care and retirement.
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Résumé Oath taking for senior executives has been promoted as a means to enhance honesty within and toward organizations. Herein we explore whether people who voluntarily sign a solemn truth-telling oath are more committed to sincere behavior when offered the chance to lie. We design an experiment to test how the oath affects truth telling in two contexts: a neutral context replicating the typical experiment in the literature, and a “loaded” context in which we remind subjects that “a lie is a lie.” We consider four payoff configurations, with differential monetary incentives to lie, implemented as within-subjects treatment variables. The results are reinforced by robustness investigations in which each subject made only one lying decision. Our results show that the oath reduces lying, especially in the loaded environment—falsehoods are reduced by 50%. The oath, however, has a weaker effect on lying in the neutral environment. The oath did affect decision times in all instances: the average person takes significantly more time deciding whether to lie under oath.
Mots clés Truth-telling oath, Lies, Deception, Laboratory Experiment
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Résumé We focus on the design of an institutional device aimed to foster coordination through communication. We explore whether the social psychology theory of commitment, implemented via a truth-telling oath, can reduce coordination failure. Using a classic coordination game, we ask all players to sign voluntarily a truth-telling oath before playing the game with cheap talk communication. Three results emerge with commitment under oath: (1) coordination increased by nearly 50 percent; (2) senders' messages were significantly more truthful and actions more efficient, and (3) receivers' trust of messages increased.
Mots clés Oath, Cheap talk communication, Coordination game
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Résumé BACKGROUND: Dementia is a prevalent condition, affecting 5-7% of people aged 60 years and older, and a leading cause of disability in people aged 60 years and older globally. We aimed to examine the association between alcohol use disorders and dementia risk, with an emphasis on early-onset dementia (1·7) in sensitivity analyses on dementia case definition (including Alzheimer's disease) or older study populations. Also, alcohol use disorders were significantly associated with all other risk factors for dementia onset (all p
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Résumé We evaluate the introduction of various forms of antihypertensive treatments in France with a distribution-sensitive cost-benefit analysis. Compared to traditional cost-benefit analysis, we implement distributional weighting based on equivalent incomes, a new concept of individual well-being that does respect individual preferences but is not subjectively welfarist. Individual preferences are estimated on the basis of a contingent valuation question, introduced into a representative survey of the French population. Compared to traditional cost-effectiveness analysis in health technology assessment, we show that it is feasible to go beyond a narrow evaluation of health outcomes while still fully exploiting the sophistication of medical information. Sensitivity analysis illustrates the relevancy of this richer welfare framework, the importance of the distinction between an ex ante and an ex post approach, and the need to consider distributional effects in a broader institutional setting.
Mots clés Equivalent income, Distributional weights, Cost-benefit analysis, Antihypertensive treatment
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Résumé Herein we explore whether a solemn oath can eliminate hypothetical bias in a voting referenda, a popular elicitation mechanism promoted in non-market valuation exercises for its incentive compatibility properties. First, we reject the null hypothesis that a hypothetical bias does not exist. Second, we observe that people who sign an oath are significantly less likely to vote for the public good in a hypothetical referenda. We complement this evidence with a self-reported measure of honesty which confirms that the oath increases truthfulness in answers. This result opens interesting avenues for improving the elicitation of preferences in the lab and beyond.
Mots clés Hypothetical bias, Oath, Preference revelation, Dichotomous Choice Mechanism
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Résumé How is one's cognitive ability related to the way one responds to strategic uncertainty? We address this question by conducting a set of experiments in simple 2 × 2 dominance solvable coordination games. Our experiments involve two main treatments: one in which two human subjects interact, and another in which one human subject interacts with a computer program whose behavior is known. By making the behavior of the computer perfectly predictable, the latter treatment eliminates strategic uncertainty. We find that subjects with higher cognitive ability are more sensitive to strategic uncertainty than those with lower cognitive ability.
Mots clés Experiment, Strategic uncertainty, Bounded rationality, Robot
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Résumé Sous l’impulsion, notamment, de l’essor de l’économie expérimentale, la littérature récente a mis en évidence un large éventail de situations dans lesquelles les incitations monétaires échouent à orienter les comportements dans le sens désiré. Ce constat conduit à rechercher des mécanismes institutionnels alternatifs, capables de se substituer aux incitations monétaires. Cet article propose une revue des travaux s’inspirant de la psychologie sociale de l’engagement afin de développer des mécanismes non monétaires susceptibles d’affecter les comportements. Ces travaux étudient une procédure d’engagement particulière : un serment à dire la vérité. Cette procédure a été appliquée avec succès (1) au problème du biais hypothétique dans la révélation des préférences pour les biens non marchands, (2) aux défauts de coordination, et (3) à la propension à dire la vérité. Pris ensemble, ces travaux confirment la capacité de mécanismes d’engagement à guider l’élaboration d’institutions non monétaires capables d’orienter efficacement les comportements économiques.
Mots clés Engagement
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Résumé Dominance solvability is one of the most straightforward solution concepts in game theory. It is based on two principles: dominance (according to which players always use their dominant strategy) and iterated dominance (according to which players always act as if others apply the principle of dominance). However, existing experimental evidence questions the empirical accuracy of dominance solvability. In this study, we study the relationships between the key facets of dominance solvability and two cognitive skills, cognitive reection and uid intelligence. We provide evidence that the behaviors in accordance with dominance and one-step iterated dominance are both predicted by one's uid intelligence rather than cognitive reection. Individual cognitive skills, however, only explain a small fraction of the observed failure of dominance solvability. The accuracy of theoretical predictions on strategic decision making thus not only depends on individual cognitive characteristics, but also, perhaps more importantly, on the decision making environment itself.
Mots clés Dominance solvability, Cognitive skills, CRT, Experiment, Raven&#039, s test
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Résumé Malgré un intérêt croissant pour les déterminants non-monétaires des comportements fiscaux (tax morale), la littérature récente apporte peu d'éléments empiriques sur le lien entre les caractéristiques de personnalité reliées à la moralité et la propension à l'évasion fiscale. Or de telles mesures sont nécessaires pour comprendre les canaux de transmission des dispositifs de lutte contre l'évasion fiscale. Pour pallier cette lacune, le présent article rend compte d'une expérience en laboratoire permettant d'observer à la fois les comportements de déclaration de revenu des participants et des mesures psychologiques issues de la littérature en psychométrie : soumission à la norme, empathie affective et cognitive, et propension à ressentir la honte et la culpabilité. Ces mesures sont combinées à l'aide d'une analyse en composantes principales afin d'en extraire les facteurs indépendants. Nos résultats montrent que la décision de frauder comme son intensité sont fortement liées à l'empathie affective, l'empathie cognitive et la dimension publique de la moralité (mesurée par la soumission à la norme et la propension à la honte). La propension à ressentir la culpabilité, en revanche, est sans effet. Surtout, le pouvoir explicatif global de ces mesures de moralité individuelles est relativement faible. Ce résultat remet en cause l'hypothèse d'une moralité fiscale intrinsèque, et met l'accent sur l'importance du contexte institutionnel pour comprendre les comportements d'évasion.
Mots clés Évasion fiscale, Traits de personnalité
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Mots clés Cheap talk communication, Oath, Coordination game
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Mots clés Cheap talk communication, Oath, Coordination game
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Résumé The log-normal distribution is convenient for modelling the income distribution, and it offers an analytical expression for most inequality indices that depends only on the shape parameter of the associated Lorenz curve. A decomposable inequality index can be implemented in the framework of a finite mixture of log-normal distributions so that overall inequality can be composed into within-subgroup components. Using a Bayesian approach and a Gibbs sampler, a Rao-Blackwellization can improve inference results on decomposable income inequality indices. The very nature of the economic question can provide prior information so as to distinguish between the income groups and construct an asymmetric prior density which can reduce label switching. Data from the UK Family Expenditure Survey (FES) (1979 to 1996) are used in an extended empirical application.
Mots clés Economie quantitative
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Résumé In this paper, we propose a behavioral approach to determine the extent to which the consumer/citizen distinction affects interpretations of monetary values in stated preferences methods. We perform a field experiment dealing with air pollution, where some (randomly selected) subjects are given the opportunity to behave politically by signing a petition for environmental protection prior to stating their private preferences in a standard contingent valuation exercise. We show that signing has the potential to influence respondents' willingness to pay values. Results indicate that even market-like situations are not immune to citizen behavior.
Mots clés Willingness to pay, Field experiment, Contingent valuation, Consumer, Commitment, Citizen, Air pollution
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Résumé Health equivalent income concept [...]
Mots clés Cost/Benefit Analysis
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Résumé This study investigates whether a popular stated preference method, the choice experiment (CE), reliably measures individuals’ values for a good. We address this question using an induced value experiment. Our results indicate that CEs fail to elicit payoff maximizing choices. We find little evidence that increasing the salience of the choices or adding monetary incentives increase the proportion of payoff maximizing choices. This questions the increasing use of CE to value non-market goods for policy making.
Mots clés Revelation, Demand
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Résumé We extend the individual dynamic model of lifetime resource allocation to assess the monetary value given to the increase in survival probabilities for every member of a household induced by improved air quality. We interpret this monetary value as VPF (value of a prevented fatality), which can also be expressed as a flow of discounted VOLY (value of life years) lost, and account for potential altruism towards other household members. We use a French air pollution contingent valuation survey that provides a description of the life-length reduction implied by a change in air pollution exposure. By privatising the public commodity air pollution, we succeed in ruling out any form of altruism (towards others living today and towards future generations) except altruism towards one's family. We estimate a mean VOLY of € 2001 140,000, a 30% premium for VOLY in perfect health w.r.t. average expected health status, and a mean VPF of € 2001 1.45 million for the respondent, all context-specific. In addition, we find an inverted U-shaped relationship between his/her age and VOLY/VPF, and significant benevolence only towards children under 18.
Mots clés Economie quantitative
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Résumé We compare two approaches to measuring inequity in the health distribution. The first is the concentration index. The second is the calculation of the inequality in an overall measure of individual well-being, capturing both the income and health dimensions. We introduce the concept of equivalent income as a measure of well-being that respects preferences with respect to the trade-off between income and health, but is not subjectively welfarist since it does not rely on the direct measurement of happiness. Using data from a representative survey in France, we show that equivalent incomes can be measured using a contingent valuation method. We present counterfactual simulations to illustrate the different perspectives of the approaches with respect to distributive justice.
Mots clés Economie quantitative
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Résumé [fr] La valorisation économique d’une diminution du risque de mortalité recourt de plus en plus fréquemment aux techniques d’évaluation contingente. Celles‑ci consistent à interroger un échantillon d’individus sur leur «consentement à payer » (CAP) pour réduire ce risque à partir de scénarios hypothétiques. Les CAP dépendent toutefois de nombreux facteurs et notamment de la nature du risque sous‑jacent et du scénario proposé pour le réduire. Cet article s’intéresse à la diminution du risque de mortalité associé à une exposition à la pollution atmosphérique et teste l’effet d’une modification du contexte d’évaluation hypothétique à travers trois scénarios : un nouveau médicament, un déménagement et de nouvelles réglementations. Pour analyser les CAP déclarés dans les différents scénarios, nous définissons un cadre d’analyse unifié, théorique puis économétrique, qui prend en compte les préférences des participants pour le présent, ainsi que celles des autres membres du ménage. Deux résultats en découlent. Les taux d’actualisation implicites estimés, spécifiques à chacun des scénarios hypothétiques, se révèlent significativement différents. De l’ordre de 7 % pour le scénario «déménagement » , ils sont respectivement de 24 % et 26 % pour les scénarios «médicament » et «réglementation » . Il en résulte des «valeurs d’évitement d’un décès » (VED) moyennes très différentes entre le scénario «déménagement » (801 000) d’une part, et les scénarios «médicament » (299 000) et «réglementation » (252 000) d’autre part. [en] The economic value placed on a reduction in the risk of mortality relies more and more frequently on contingent assessment techniques. These consist in questioning a sample of individuals on their “ willingness to pay” (WTP) in order to reduce this risk, on the basis of hypothetical scenarios. These WTP nevertheless depend on many factors, especially the nature of the underlying risk and the scenario proposed to reduce it. This article deals with reducing the risk of mortality associated with exposure to atmospheric pollution and tests the effect of a change in the hypothetical context of assessment through three scenarios : a new drug, a house move and new regulations. To analyse the “ willingness to pay” stated in the different scenarios, we define a unified, theoretical then econometric framework of analysis, taking into account the preferences of the participants at present, and also those of other household members. There are two main results. The estimated implicit updating rates, specific to each hypothetical scenario, were seen to differ significantly. They were about 7% for the “ move” scenario and 24% and 26% for the “ drugs” and “ regulations” scenarios respectively. Results showed that the average “ values set for avoiding death” differed greatly between the “ move” scenario (801,000) on the one hand, and the “ drugs” (299,000) and “ regulations” (252,000) scenarios on the other hand.
Mots clés Economie quantitative
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Résumé We argue that the economic evaluation of health care (cost–benefit analysis) should respect individual preferences and should incorporate distributional considerations. Relying on individual preferences does not imply subjective welfarism. We propose a particular non-welfarist approach, based on the concept of equivalent income, and show how it helps to define distributional weights. We illustrate the feasibility of our approach with empirical results from a pilot survey.
Mots clés Economie quantitative
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Résumé Deux méthodes sont généralement envisagées pour l'évaluation des politiques de santé. L'approche coût-bénéfice s'appuie sur la somme des consentements individuels à payer : elle respecte les préférences individuelles mais elle donne une priorité aux préférences des plus riches car leurs consentements à payer sont en général plus élevés. L'approche coût-efficacité sélectionne les politiques assurant le gain le plus élevé en matière de santé globale, à coût total donné. Elle n'avantage pas les individus à revenu élevé, mais elle peut avoir d'autres effets indésirables : par exemple favoriser le traitement d'une affection bénigne qui profitera au plus grand nombre par rapport à une affection grave touchant peu de personnes. Une variante de l'analyse coût-bénéfice évite ces différents écueils. Elle consiste à pondérer les consentements à payer par des coefficients qui varient en sens inverse d'un indicateur de bien-être individuel combinant revenu et état de santé. L'indicateur choisi est le revenu équivalent santé : il s'agit du revenu effectif de l'individu diminué du montant auquel il serait prêt à renoncer pour être en parfaite santé. À revenu donné, il décroit donc quand la santé se détériore. Contrairement à des indices d'utilité subjective, il a l'avantage de ne s'appuyer que sur les préférences ordinales des individus. Cette approche est mise en œuvre à l'aide d'une enquête conduite sur un échantillon représentatif de la population française. Compte tenu de leurs contraintes financières, les personnes à bas revenu accordent moins d'importance relative à leur état de santé. Mais les coefficients obtenus permettent néanmoins de surpondérer les individus les moins favorisés cumulant faible revenu, mauvaise santé et forte préférence pour l'amélioration de cette santé. Ces coefficients sont ensuite mobilisables pour l'évaluation de toute politique pour laquelle on connaitrait les consentements individuels à payer.
Mots clés Economie quantitative
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Résumé Eliciting sincere preferences for non-market goods remain a challenge due to the discrepency between hypothetical and real behavior and false zeros. The gap arises because people either overstate hypothetical values or understate real commitments or a combination of both. Herein we examine whether the traditional real-world institution of the solemn oath can improve preference elicitation. Applying the social psychology theory on the oath as a truth-telling-commitment device, we ask our bidders to swear on their honour to give honest answers prior to participating in an incentive-compatible second-price auction. The oath is an ancillary mechanism to commit bidders to bid sincerely in a second-price auction. Results from our induced valuation testbed treatments suggest that the oath-only auctions outperform all our other auctions (real and hypothetical). In our homegrown valuation treatments eliciting preferences for dolphin protection, the oath-only design induced people to treat as binding both their experimental budget constraint (i.e., lower values on the high end of the value distribution) and participation constraint (i.e., positive values in place of the zero bids used to opt-out of auction). Based on companion treatments, we show the oath works through an increase in the willingness to tell the truth, due to a strengthening of the intrinsic motivation to do so.
Mots clés Oath, Commitment, Vickrey auction, Hypothetical bias, Induced values, Homegrown values
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Résumé Many stated preference studies report framing effects in responses to valuation questions. Framing in stated preference studies occurs when respondents use irrelevant information contained in the question to help them value the good. This may occur because respondents are uncertain or do not hold well-formed preferences for the good in question. We investigate if respondent certainty explains framing effects in a contingent valuation study, using data from a double bounded dichotomous elicitation format and a follow-up certainty question. We investigate if respondent certainty influences anchoring and the shift effect. We find evidence that the anchoring effect is stronger for respondents who are less certain about their response to the contingent valuation question compared to respondents who are very certain. However, the shift effect is significant and negative only for respondents who are very certain. Our results indicate that certain respondents are more consistent with the predictions of rational behaviour than uncertain respondents.
Mots clés Contingent, Valuation
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Résumé The field of social psychology explores how a person behaves within the context of other people. The social context can play a substantive role in non-market allocation decisions given peoples choices and values extend beyond the classic market-based exchange institution. Herein we explore how social psychology has affected one aspect of environmental economics: preference elicitation through survey work. We discuss social representation, social isolation, framing through cheap talk, and commitment theory through an oath.
Mots clés Social psychology, Commitment, Persuasive communication, Preference elicitation
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Résumé Hypothetical bias is a long-standing issue in stated preference and contingent valuation studies - people tend to overstate their preferences when they do not experience the real monetary consequences of their decision. This view, however, has been challenged by recent evidence based on the elicitation of induced values (IV) in the lab and homegrown (HG) demand function from different countries. This paper uses an experimental design to assess the extent and relevance of hypothetical bias in demand elicitation exercises for both IV and HG values. For testbed purpose, we use a classic second-price auction to elicit preferences. Comparing the demand curve we elicit in both, hypothetical bias unambiguously (i) vanishes in an induced-value, private good context, and (ii) persists in homegrown values elicitation context. This suggests hypothetical bias in preference elicitation appears to be driven by "preference formation" rather than "preference elicitation". In addition, companion treatments highlight two sources of the discrepancy observed in the HG setting: the hypothetical context leads bidders to underestimate the constraints imposed by their budget limitations, whereas the real context creates pressure leading them to bid "zero" to opt out from the elicitation mechanism. As a result, there is a need for a demand elicitation procedure that helps subjects take the valuation exercise sincerely, but without putting extra pressure on them.
Mots clés Auctions, Demand revelation, Experimental valuation, Hypothetical bias
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Résumé Vaccination campaigns to prevent the spread of epidemics are successful only if the targeted populations subscribe to the recommendations of health authorities. However, because compulsory vaccination is hardly conceivable in modern democracies, governments need to convince their populations through efficient and persuasive information campaigns. In the context of the swine-origin A (H1N1) 2009 pandemic, we use an interactive study among the general public in the South of France, with 175 participants, to explore what type of information can induce change in vaccination intentions at both aggregate and individual levels.We find that individual attitudes to vaccination are based on rational appraisal of the situation, and that it is information of a purely scientific nature that has the only significant positive effect on intention to vaccinate.
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Résumé Vaccination campaigns to prevent the spread of epidemics are successful only if the targeted populations subscribe to the recommendations of health authorities. However, because compulsory vaccination is hardly conceivable in modern democracies, governments need to convince their populations through efficient and persuasive information campaigns. In the context of the swine-origin A (H1N1) 2009 pandemic, we use an interactive study among the general public in the South of France, with 175 participants, to explore what type of information can induce change in vaccination intentions at both aggregate and individual levels. We find that individual attitudes to vaccination are based on rational appraisal of the situation, and that it is information of a purely scientific nature that has the only significant positive effect on intention to vaccinate.
Mots clés Information, Vaccination, Influenza A H1N1, Attitudes, Interactive, Experiment, France, Experience, Grippe A
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Résumé Environmental economics is now a long standing field of research; much has been learned on how environmental policy can use incentives to drive individual behaviors. Among the many examples, preference elicitation is the most discussed case in which incentives fail to accurately implement efficient behavior. Using this as our motivating example, herein we explore the cross-fertilization between environmental economics and social psychology. We first review how the lessons drawn from social psychology helped address the hypothetical bias issue. We then turn to the future of this process by focusing on how cheap talk scripts influence preference elicitation. Our experimental results shows CT scripts work through persuasion – i.e. changes mind, but poorly changes actions. in that sense, preference elicitation still lacks a way of making communication binding – i.e. a way to alter intrinsic motivation of subjects to behave truthfully.
Mots clés Social psychology, Commitment, Persuasive communication, Preference elicitation, Psychologie sociale, Engagement, Communication persuasive, Révélation des préférences
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Résumé In this paper, we consider that our experience of time (to come) depends on the emotions we feel when we imagine future pleasant or unpleasant events. A positive emotion such as relief or joy associated with a pleasant event that will happen in the future induces impatience. Impatience, in our context, implies that the experience of time up to the forthcoming event expands. A negative emotion such as grief or frustration associated with an unpleasant event that will happen in the future triggers anxiety. This will give the experience of time contraction. Time, therefore, is not exogeneously given to the individual and emotions, which link together events or situations, are a constitutive ingredient of the experience of time. Our theory can explain experimental evidence that people tend to prefer to perform painful actions earlier than pleasurable ones, contrary to the predictions yielded by the standard exponential discounting framework.
Mots clés Experience of time, Emotions, Impatience, Anxiety, Discount factor, Time preference
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Résumé BACKGROUND: Hepatitis C virus (HCV) recently emerged as a major public health hazard in Egypt. However, dramatic healthcare budget constraints limit access to the costly treatment. We assessed risk perception and priority setting for intervention among HCV, unsafe water, and outdoor air pollution in Cairo city. METHODS: A survey was conducted in the homes of a representative sample of household heads in Cairo city. Risk perception was assessed using the "psychometric paradigm" where health hazards are evaluated according to several attributes and then summarized by principal component analysis. Priority setting was assessed by individual ranking of interventions reducing health hazards by 50% over five years. The Condorcet method was used to aggregate individual rankings of the three interventions (main study) or two of three interventions (validation study). Explanatory factors of priority setting were explored in multivariate generalized logistic models. RESULTS: HCV was perceived as having the most severe consequences in terms of illness and out-of-pocket costs, while outdoor air pollution was perceived as the most uncontrollable risk. In the main study (n = 2,603), improved water supply received higher priority than both improved outdoor air quality (60.1%, P < .0001) and screening and treatment of chronic hepatitis C (66.3%, P < .0001), as confirmed in the validation study (n = 1,019). Higher education, report of HCV-related diseases in the household, and perception of HCV as the most severe risk were significantly associated to setting HCV treatment as the first priority. CONCLUSIONS: The Cairo community prefers to further improving water supply as compared to improved outdoor air quality and screening and treatment of chronic hepatitis C.
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Résumé This paper considers whether earned wealth affects bidding behavior in an induced-value second-price auction. We find people bid more sincerely in the auction with earned wealth given monetary incentives; earned wealth did not induce sincere bidding in hypothetical auctions.
Mots clés Auctions, Demand revelation, Experimental valuation, Hypothetical bias, Earned money
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Résumé The small sample size of contingent valuation (CV) surveys conducted in patients may have limited the use of the single-bounded (SB) dichotomous choice format which is recommended in environmental economics. In this paper, we explore two ways to increase the statistical efficiency of the SB format: (1) by the inclusion of proxies in addition to patients; (2) by the addition of a follow-up dichotomous question, i.e. the double-bounded (DB) dichotomous choice format. We found that patients (n=223) and spouses (n=64) answering on behalf of the patient had on average a similar willingness-to-pay for earlier alleviation of flu symptoms. However, a patient was significantly more likely to anchor his/her answer on the first bid as compared to a spouse. Finally, our original DB model with shift effect and heterogeneous anchoring reconciled the discrepancies found in willingness-to-pay statistics between SB and DB models in keeping with increased statistical efficiency.
Mots clés Contingent valuation, Double-bounded dichotomous choice, Patient, Proxy, Anchoring, Structural shift, Influenza
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Résumé Eliciting sincere preferences for non-market goods remains a challenge due to hypothetical bias - the so-called gap between hypothetical monetary values and real economic commitments. The gap arises because people either overstate hypothetical values or understate real commitments or a combination of both. Herein we examine whether the traditional real-world institution of the solenn oath can improve preference elicitation. Applying the social psychology theory on the oath as a truth-telling-commitment device, we ask our bidders to swear on their honour to give honest answers prior to participating in an incentive-compatible second-price auction. Results from our induced valuation testbed treatments suggest the oath-only auctions outperform all other auctions (real, hypothetical, and real-with-oath). In our homegrown valuation treatments eliciting preferences for dolphin protection, the oath-only design induced people to treat as binding both their budget constraint (i.e., lower values on the high end of the value distribution) and participation constraint (i.e., positive values rather than zero bids used to opt out of auction). Our oath-only results are robust to extra training on the auction and to consequential wording about the reason for the oath.
Mots clés Oath, Homegrown values, Induced values, Hypothetical bias, Vickrey auction, Commitment, Homegrown values, Serment, Engagement, Enchère à la Vickrey, Biais hypothétique, Valeurs induites, Valeurs réelles
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Résumé This article addresses the important issue of anchoring in contingent valuation surveys that use the double-bounded elicitation format. Anchoring occurs when responses to the follow-up dichotomous choice valuation question are influenced by the bid presented in the initial dichotomous choice question. Specifically, we adapt a theory from psychology to characterize respondents as those who are likely to anchor and those who are not. Using a model developed by Herriges and Shogren (1996), our method appears successful in discriminating between those who anchor and those who did not. An important result is that when controlling for anchoring - and allowing the degree of anchoring to differ between respondent groups - the efficiency of the double-bounded welfare estimate is greater than for the initial dichotomous choice question. This contrasts with earlier research that finds that the potential efficiency gain from the double-bounded questions is lost when anchoring is controlled for and that we are better off not asking follow-up questions.
Mots clés Anchoring, Contingent valuation, Heterogeneity, Framing effects
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Résumé L'évaluation de politiques de prévention sanitaire par le recours à des Consentements A Payer (CAP) issus d'enquêtes auprès de la population est de plus en plus fréquent. Lorsque ces politiques revêtent une dimension collective, les CAP déclarés par les individus peuvent refléter une composante altruiste, ce qui rend problématique le calcul économique. A partir d'une enquête d'évaluation contingente portant sur deux politiques de prévention de la Fièvre Q, l'une collective et l'autre individuelle, nous mobilisons le cadre théorique de l'utilité espérée pour déterminer le caractère altruiste (ou non) des individus, que nous expliquons ensuite par certaines de leurs caractéristiques socio-économiques. Le principal résultat est que 66% des répondants incluent une composante altruiste lors de la révélation du CAP pour le programme collectif. Elle représente 3,6 euro en moyenne, soit environ 25% du CAP considéré.
Mots clés Altruisme
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Résumé The usual implementation of contingent valuation (CV), in the context of priorities setting for allocation of public funds in health care, is to develop as many surveys as there are programmes, i.e. to perform separate evaluations (SE). In the EuroWill project, three health programmes (for heart disease, breast cancer and a service of helicopter ambulance) were however simultaneously evaluated, i.e. a joint evaluation (JE) was performed. The paper examines the issue of the econometric techniques that should be used to estimate WTP values obtained in the context of JE by comparing the application of independent OLS regressions for each programme versus simultaneous estimations using seemingly unrelated regressions (SUR) on data of the French EuroWill survey. It shows that separate estimations may lead to misspecifications because they cannot take into account that JE exogenously provides a reference structure to the respondent which affects the estimates of WTP for each programme. Therefore, the potential advantage of JE versus SE as an elicitation technique in CV studies applied to health care (to better control the referents used by respondents for evaluating different programmes) only holds if simultaneous rather than independent techniques are used in the estimation of WTPs.
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Résumé Approche critique et mise en oeuvre de la méthode d'évaluation contingente : un dialogue entre économiste et sociologue CÉCILIA CLAEYS-MEKDADE, GHISLAIN GENIAUX, STÉPHANE LUCHINI La méthode d'évaluation contingente (MEC) est un outil forgé et mis en pratique par des économistes. Mais elle utilise la technique du questionnaire individuel qui est une des techniques usuelles des sociologues. Il paraÎt donc justifié et opportun de demander à ces derniers d'apprécier de leur propre point de vue la démarche de J'économiste et en particulier de dire comment les réponses obtenues font sens pour eux. En fait, cette confrontation est exceptionnelle. L'intérêt du texte qui suit est de rendre compte d'un cas où économistes et sociologues l'ont tentée, même si ce n'est qu'a posteriori, une fois la recherche des économistes terminée. Cet article présente les principaux résultats d'une mise en oeuvre critique de la méthode d'évaluation contin-gente, réalisée dans le cadre d'un programme de recherche engagé par le GIP-Hydrosystème en 1995. lobjectif de ce programme était de promouvoir les développements théoriques et méthodologiques en matière de mesure des bénéfices liés aux hydrosys-tèmes. létude sur laquelle s'appuie cet article est une enquête d'évaluation contingente menée auprès d'un certain type d'usagers de la Camargue : les • touristes verts • 1. Elle concerne donc l'appréciation des béné-fices récréatifs attachés à l'écosystème camarguais. Dans le cadre de cette étude, nous avons été conduits à centrer les questionnements sur le rôle du contexte dans la MEC pour des raisons tenant aussi bien aux centres de recherches impliqués 2 dans l'étude qu'aux questions émergentes de la littérature sur le sujet. L'article de Willinger (1996), paru dans Natures Sciences Sociétés (NSS), affichait déjà des questionnements du même ordre. Ainsi, la probléma-tique centrale de cette étude était fortement orientée vers la théorie économique, bien que ces questions amènent la collaboration avec d'autres sciences humaines. Pour ce qui concerne cette étude, la mise en oeuvre d'un questionnaire d'évaluation contingente intégrant des questions ouvertes relatives aux perceptions individuelles de l'objet évalué et du contexte d'évaluation fut le point de départ d'une prise en compte du contexte social. Située en aval de l'en-quête, l'intervention de la sociologie eut pour vocation de fournir des éléments méthodologiques utilisables dans la méthode d'évaluation contingente. En ce sens, un travail d'analyse sociologique approfondi ne peut se contenter des seules informations collectées dans cette enquête. Cependant, l'analyse ici effectuée permet de proposer un éclairage critique de la notion de contexte social appliquée à la méthode d'évalua-tion contingente. Cet article prend la forme d'un dialogue critique autour de la méthode d'évaluation contingente. Aux termes de ce travail, nous faisons plusieurs propositions pour une amélioration de la méthode, tout en gardant une position nuancée. En effet, les résultats obtenus et les réflexions engagées semblent confirmer les difficultés inhérentes à la méthode, d'un point de vue théorique et méthodologique. Après une présentation de la MEC, nous passons en revue la littérature interdisciplinaire économie-psycho-logie et psychologie sociale sur le sujet. Concluant sur le constat d'une faiblesse de ces analyses concernant la prise en compte du contexte social et des normes sociales, s'entame alors un nécessaire dialogue entre économie et sociologie. En un troisième temps, nous proposons quelques éléments de réflexion autour de Abstract-Critical approach and application of the contingent valuation method. A dialogue between sociology and economy This article introduces the main results of a critical implementation of the contingent valuation method which was carried out within a research programme thal GIP-Hydrosystème started in 1995. lt is based on a contingent valuation survey which involves a specifie group of users of the Camargue a rea: the ·green tourists· and it therefore refers to estimating the recreation advantages related to the Camargue ecosystem. When data were processed and results were analysed, economy, which the method results from, ca lied for the sociologist's critical eye. A critical dialogue about the contingent valuation method a rose from this collaboration. At the end of this work, we make several proposais to improve the method as we lake a moderate stance about how far it can be applied.
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Résumé We provide a novel way to correct the effective reproduction number for the time-varying amount of tests, using the acceleration index (Baunez et al., 2021) as a simple measure of viral spread dynamics. Not correcting results in the reproduction number being a biased estimate of viral acceleration and we provide a formal decomposition of the resulting bias, involving the useful notions of test and infectivity intensities. When applied to French data for the COVID-19 pandemic (May 13, 2020 - October 26, 2022), our decomposition shows that the reproduction number, when considered alone, characteristically underestimates the resurgence of the pandemic, compared to the acceleration index which accounts for the time-varying volume of tests. Because the acceleration index aggregates all relevant information and captures in real time the sizable time variation featured by viral circulation, it is a more parsimonious indicator to track the dynamics of an infectious disease outbreak in real time, compared to the equivalent alternative which would combine the reproduction number with the test and infectivity intensities
Mots clés COVID-19, Reproduction Number, TESTING, Acceleration Index, Real-time Analysis, France
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Résumé Objectives: This note provides an assessment of COVID-19 acceleration among groups with different vaccine status in France. Methods: We assess viral acceleration using a novel indicator introduced in Baunez et al. (2021). The acceleration index relates the percentage change of tests that have been performed on a given day to the percentage change in the associated positive cases that same day. We compare viral acceleration among vaccinated and unvaccinated individuals in France over the period May 31st-August 29, 2021. Results: Once the state of the epidemic within each groups is accounted for, it turns out that viral acceleration has since mid-July converged to similar levels among vaccinated and unvaccinated individuals in France, even though viral speed is larger for the latter group compared to the former. Conclusion: Our results call for an increasing testing effort for both vaccinated and unvaccinated individuals, in view of the fact that viral circulation is currently accelerating at similar levels for both groups in France.
Mots clés COVID-19, Vaccine Status, Viral Acceleration, Acceleration Index, France
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Résumé An acceleration index is proposed as a novel indicator to track the dynamics of COVID-19 in real-time. Using data on cases and tests in France for the period between the first and second lock-downs-May 13 to October 25, 2020-our acceleration index shows that the pandemic resurgence can be dated to begin around July 7. It uncovers that the pandemic acceleration was stronger than national average for the [59-68] and especially the 69 and older age groups since early September, the latter being associated with the strongest acceleration index, as of October 25. In contrast, acceleration among the [19-28] age group was the lowest and is about half that of the [69-78]. In addition, we propose an algorithm to allocate tests among French "dé partements" (roughly counties), based on both the acceleration index and the feedback effect of testing. Our acceleration-based allocation differs from the actual distribution over French territories, which is population-based. We argue that both our acceleration index and our allocation algorithm are useful tools to guide public health policies as France might possibly enter a third lock-down period with indeterminate duration.
Mots clés France, Sub-national allocation of tests, Real-time Analysis, Acceleration Index, Indicator of epidemic dynamics, COVID-19
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Résumé Even though much has been learned about the new pathogen SARS-CoV-2 since the beginning of the COVID-19 pandemic, a lot of uncertainty remains. In this paper we argue that what is important to know under uncertainty is whether harm accelerates and whether health policies achieve deceleration of harm. For this, we need to see cases in relation to diagnostic effort and not to look at indicators based on cases only, such as a number of widely used epidemiological indicators, including the reproduction number, do. To do so overlooks a crucial dimension, namely the fact that the best we can know about cases will depend on some welldefined strategy of diagnostic effort, such as testing in the case of COVID-19. We will present a newly developed indicator to observe harm, the acceleration index, which is essentially an elasticity of cases in relation to tests. We will discuss what efficiency of testing means and propose that the corresponding health policy goal should be to find ever fewer cases with an ever-greater diagnostic effort. Easy and low-threshold testing will also be a means to give back people’s sovereignty to lead their life in an “open” as opposed to “locked-down” society.
Mots clés Uncertainty, Acceleration Index, Anti-fragility, Reproduction factor, Test strategy, Sovereignty
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Résumé We show that the acceleration index, a novel indicator that measures acceleration and deceleration of viral spread (Baunez et al. 2020a,b), is essentially a test-controlled version of the reproduction number. As such it is a more accurate indicator to track the dynamics of an infectious disease outbreak in real time. We indicate a discrepancy between the acceleration index and the reproduction number, based on the infectivity and test rates and we provide a formal decomposition of this difference. When applied to French data for the ongoing COVID-19 pandemic, our decomposition shows that the reproduction number consistently underestimates the resurgence of the pandemic since the summer of 2020, compared to the acceleration index which accounts for the time-varying volume of tests. Because the acceleration index aggregates all the relevant information and captures in real time the sizeable time variation featured by viral circulation, it is a sufficient statistic to track the pandemic’s propagation.
Mots clés COVID-19, Reproduction Number, Lock-down, Acceleration Index, Real-time Analysis, France
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Résumé This note provides an early assessment of the reinforced measures to curb the COVID-19 pandemic in France, which include a curfew of selected areas and culminate in a second COVID-19-related lock-down that started on October 30, 2020 and is still ongoing. We analyse the change in virus propagation across age groups and across départements using an acceleration index introduced in Baunez et al. (2020). We find that while the pandemic is still in the acceleration regime, acceleration decreased notably with curfew measures and this more rapidly so for the more vulnerable population group, that is, for people older than 60. Acceleration continued to decline under lock-down, but more so for the active population under 60 than for those above 60. For the youngest population aged 0 to 19, curfew measures did not reduce acceleration but lock-down does. This suggests that if health policies aim at protecting the elderly population generally more at risk to suffer severe consequences from COVID-19, curfew measures may be effective enough. However, looking at the departmental map of France, we find that curfews have not necessarily been imposed in départements where acceleration was the largest.
Mots clés COVID-19, Effects of curfew and lock-down, Acceleration Index, Real-time Analysis, France
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Résumé An acceleration index is proposed as a novel indicator to track the dynamics of the COVID-19 in real-time. Using French data on cases and tests for the period following the first lock-down-from May 13, 2020, onwards-our acceleration index shows that the ongoing pandemic resurgence can be dated to begin around July 7. It uncovers that the pandemic acceleration has been stronger than national average for the [59 − 68] and especially the 69 and older age groups since early September, the latter being associated with the strongest acceleration index, as of October 25. In contrast, acceleration among the [19 − 28] age group is the lowest and is about half that of the [69 − 78], as of October 25. In addition, we propose an algorithm to allocate tests among French départements, based on both the acceleration index and the feedback effect of testing. Our acceleration-based allocation differs from the actual distribution over French territories, which is population-based. We argue that both our acceleration index and our allocation algorithm are useful tools to guide public health policies as France enters a second lock-down period with indeterminate duration.
Mots clés COVID-19, Indicator of epidemic dynamics, Acceleration Index, Real-time Analysis, Sub-national allocation of tests, France
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Résumé Tests are crucial to know about the number of people who have fallen ill with COVID-19 and to understand in real-time whether the dynamics of the pandemic is accelerating or decelerating. But tests are a scarce resource in many countries. The key but still open question is thus how to allocate tests across sub-national levels. We provide a data-driven and operational criterion to allocate tests efficiently across regions or provinces, with the view to maximize detection of people who have been infected. We apply our criterion to Italian regions and compute the shares of tests that should go to each region, which are shown to differ significantly from the actual distribution.
Mots clés COVID-19, Italy, Acceleration of harm, Deceleration of harm, Epidemic dynamics, Efficiency criterion, Sub-national allocation of tests, Real-time Analysis
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Résumé Tests are crucial to know about the number of people who have fallen ill with COVID-19 and to understand in real-time whether the dynamics of the pandemic is accelerating or decelerating. But tests are a scarce resource in many countries. The key but still open question is thus how to allocate tests across sub-national levels. We provide a data-driven and operational criterion to allocate tests efficiently across regions or provinces, with the view to maximize detection of people who have been infected. We apply our criterion to Italian regions and compute the shares of tests that should go to each region, which are shown to differ significantly from the actual distribution.
Mots clés Sub-national allocation of tests, Real-time Analysis, COVID-19, Epidemic dynamics, Acceleration of harm, Deceleration of harm, Italy, Efficiency criterion
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Résumé The radical uncertainty around the current COVID19 pandemics requires that governments around the world should be able to track in real time not only how the virus spreads but, most importantly, what policies are effective in keeping the spread of the disease under check. To improve the quality of health decision-making, we argue that it is necessary to monitor and compare acceleration/deceleration of confirmed cases over health policy responses, across countries. To do so, we provide a simple mathematical tool to estimate the convexity/concavity of trends in epidemiological surveillance data. Had it been applied at the onset of the crisis, it would have offered more opportunities to measure the impact of the policies undertaken in different Asian countries, and to allow European and North-American governments to draw quicker lessons from these Asian experiences when making policy decisions. Our tool can be especially useful as the epidemic is currently extending to lower-income African and South American countries, some of which have weaker health systems.
Mots clés Acceleration, Convexity, COVID-19, Data Dashboard, Detection of Infectious Diseases, Public Health Policy, Sensitivity
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Résumé How is one's cognitive ability related to the way one responds to strategic uncertainty? We address this question by conducting a set of experiments in simple 2 × 2 dominance solvable coordination games. Our experiments involve two main treatments: one in which two human subjects interact, and another in which one human subject interacts with a computer program whose behavior is known. By making the behavior of the computer perfectly predictable, the latter treatment eliminates strategic uncertainty. We find that subjects with higher cognitive abilities are more sensitive to strategic uncertainty than those with lower cognitive abilities.
Mots clés Experiment, Robot, Strategic uncertainty, Bounded rationality
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