Addressing COVID-19 vaccine hesitancy: is official communication the key?Journal articleMichael Schwarzinger et Stéphane Luchini, The Lancet Public Health, Volume 6, Issue 6, pp. e353-e354, 2021


COVID-19 vaccine hesitancy in a representative working-age population in France: a survey experiment based on vaccine characteristicsJournal articleMichael Schwarzinger, Verity Watson, Pierre Arwidson, François Alla et Stéphane Luchini, The Lancet Public Health, Volume 6, Issue 4, pp. e210-e221, 2021

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.
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).
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]).
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.
French Public Health Agency (Santé Publique France).

Comment lutter contre la fraude fiscale ?Book chapterNicolas Jacquemet, Stéphane Luchini et Antoine Malézieux, In: Les français et l'argent : 6 nouvelles questions d'économie contemporaine, D. Cohen et C. Senik (Eds.), 2021-03, pp. Chap.3, Albin Michel, 2021


Does charity begin at home for air pollution reductions? Unraveling intra familial altruismJournal articleOlivier Chanel, Stéphane Luchini et Jason F. Shogren, Journal of Choice Modelling, Volume 38, pp. 100268, 2021

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.

Do truth-telling oaths improve honesty in crowd-working?Journal articleNicolas Jacquemet, Alexander G. James, Stéphane Luchini, James J. Murphy et Jason F. Shogren, PLoS ONE, Volume 16, Issue 1, pp. e0244958, 2021

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.

Sub-national allocation of COVID-19 tests: An efficiency criterion with an application to Italian regionsJournal articleChristelle Baunez, Mickael Degoulet, Stéphane Luchini, Patrick A. Pintus et Miriam Teschl, Covid Economics, Volume 12, pp. 192-209, 2020

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.Mickael Degoule

Who’ll stop lying under oath? Empirical evidence from tax evasion gamesJournal articleNicolas Jacquemet, Stéphane Luchini, Antoine Malézieux et Jason F. Shogren, European Economic Review, Volume 124, pp. 103369, 2020

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.

Chapter 4 - Monetary analysis of health outcomesBook chapterVerity Watson, Stéphane Luchini, Dean Regier et Rainer Schulz, In: Cost-Benefit Analysis of Environmental Health Interventions, Carla Guerriero (Eds.), 2020-01, pp. 73-93, Academic Press, 2020

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.

Comment lutter contre la fraude fiscale ? Les enseignements de l’économie comportementaleBookNicolas Jacquemet, Stéphane Luchini et Antoine Malézieux, CEPREMAP, 2020, Number 53, 104 pages, Rue d'Ulm, 2020

La fraude fiscale est un sujet qui se dérobe aux outils de l’analyse économique traditionnelle. D’une part, comme toute activité illégale, la fraude 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 la fraude 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 la fraude 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 de fraude 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.

Clinical and economic burden of head and neck cancer: a nationwide retrospective cohort study from FranceJournal articleAntoine Schernberg, Luis Sagaon-Teyssier, Michael Schwarzinger, Stéphane Luchini, ClinicoEconomics and Outcomes Research, Volume 11, pp. 441-451, 2019

To evaluate the clinical and economic burden of head and neck squamous cell carcinoma (HNSCC) in France.

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.

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<0.001). HNSCC stage at initial treatment was the major driver of mean (SD) direct costs over 3 years (p<0.001): 19,819 (23,150) euros in 31% patients diagnosed at early stage; 46,791 (34,841) euros in 60% patients diagnosed at locally advanced stage; and 43,377 (33,953) euros in 9% patients diagnosed with distant metastasis. About half patients died over 3 years at a median (IQR) age of 63 (56–75) years resulting in 10.9 years-of-life lost on average per incident patient.

The present study suggests that the clinical and economic burden of HNSCC is substantial in France.