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Les analyses coûts-bénéfices constituent un moyen pour le décideur public comme privé de rationaliser ses choix. Le processus semble transparent et le traitement des préférences égalitaire, puisque les préférences de chaque individu sont prises en compte de façon similaire lors de l’agrégation. Toutefois, en présence de composantes non marchandes évaluées sur la base des préférences de la population, les individus sont limités dans l’expression de leurs préférences, à la fois par leur revenu et par leur besoin de subsistance. Nous étudions les conséquences de ces contraintes sur la révélation des préférences et sur l’évaluation monétaire des biens non marchands. Nous trouvons qu’elles amènent à favoriser implicitement les préférences des individus à revenu élevé. Se pose alors la question de la correction des évaluations monétaires lors du traitement des préférences individuelles.
The elicitation format is a crucial aspect of Contingent Valuation (CV) surveys and can impact their reliability. This paper contributes to the extensive debate on WTP (Willingness To Pay) elicitation formats by assessing whether the Circular Payment Card (CPC) can reduce anchoring on respondents' previous answers under multiple elicitation questions. This new format uses a visual pie-chart representation without start or end points: respondents spin the circular card in any direction until they find the section that best matches their WTP. We used a CV survey based on two ways of reducing risks associated with flooding, each randomly presented first to half of the respondents, to test the absolute performance of CPC. We presented a second survey on two social insurance schemes for subjects currently uninsured to respondents randomly split into three subgroups. Each group's WTP was elicited using one of three formats: Open-Ended (OE), standard Payment Card (PC) and the new CPC. The two insurance schemes were always proposed in the same order, and we assessed the relative performance of CPC by comparing anchoring across respondents. Our results provide evidence that CPC is likely to reduce anchoring in multiple elicitation questions and that respondents may rely on different heuristic decisions when giving WTP in the OE and in the two PC formats.
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.
Ce document évalue monétairement les impacts de l’exposition chronique aux particules fines sur la mortalité calculés par Santé publique France (Pascal et al., 2016a, 2016b) en France continentale. Il reprend les 5 scénarios de réduction retenus et les deux méthodes de mesure de la mortalité : en nombre de décès prématurés évités et en nombre total d’années de vie gagnées. Les calculs sont effectués pour la France continentale entière, et pour chacune des 12 nouvelles régions. Ils apportent un argument supplémentaire sur la nécessité de réduire l’exposition des populations à la pollution de l’air ambiant en France. Une synthèse est disponible dans Chanel (2017).
Natural disasters due to climate change (like floods, hurricanes, heat waves or droughts) combine a risk of large losses and a low probability of occurrence, requiring decisions to be made in uncertain universes. However, the inability of standard decision under uncertainty models to provide rankings when some outcomes are catastrophic impedes rational (public) decision-making. This paper examines the role of emotions in individuals’ choices among alternatives involving catastrophic events, either in real life (flooding) or artificial (laboratory experiment) situations. We report a survey on 599 respondents aimed at determining how people exposed to different levels of flood risk form beliefs and make decisions under uncertainty before and after emotion-generating events. Data on their emotions, the emotions they expect to experience, their personality and psychological determinants, their symptoms before and after emotion-generating events are collected and analyzed. In parallel with this survey, experimental protocols replicate the emotional experience of a catastrophe and measure its impact on behavior and formation of beliefs. Emotions are induced by framing effects and measured through a self-declared worry scale. We collect behavioral data (insurance choice, subjective beliefs, performance) and measure how they are affected by the emotions felt during the decision-making. These protocols test some assumptions in the survey using experimental paradigms from psychophysics that allow us to control the sources of uncertainty experienced by the subjects. Results confirm that emotions connected with the nature of the risk can significantly affect desire to reduce it. The survey provides valuable material for comparative analysis, revealing how actual experience of an anticipated event affects decisions. The experiments show that emotions affect the decision-making process and the forming of probabilistic beliefs.
This paper analyses how French general practitioners? (GPs) labour supply would respond to changes in their fee per consultation, seeking to determine whether there is a backward-bending curve.?Because French GPs? fees only evolve very slowly and are generally fixed by the National Health Insurance Fund, fee variability is not sufficient to observe changes in labour supply.?Therefore, we designed a contingent valuation survey randomly presenting GPs with three hypothetical fee increases.?Empirical evidence from 1,400 GPs supports the hypothesis of a negative slope in their labour supply curve.?This suggests that increasing fees is not an effective policy to increase the supply of medical services. JEL Codes: C21, I12, J22, J4.
BRCA1/2 carriers have a higher risk of developing breast and ovarian cancer at a younger age. Preimplantation genetic diagnosis (PGD) and prenatal diagnosis (PND) are two of the few options available to avoid transmitting the mutation. To inform the bioethics debate about authorization, a contingent valuation survey elicited preferences regarding access to PGD and PND from a sample of 460 unaffected by cancer BRCA1/2 carriers (GENEPSO cohort). We find that the respondents can be classified into three groups: one opposed to PGD/PND (28.3%), one strongly in favour of PGD/PND (45.8%), and one in an intermediate position (25.9%). We look for the determinants of these preferences, especially of the willingness to pay for PGD/PND. Overall, we find that BRCA1/2 carriers support access to PGD/PND, which has implications for recommendations to decision-makers.
The choice of elicitation format is a crucial but tricky aspect of stated preferences surveys. It affects not only the quantity and quality of the information collected on respondents’ willingness to pay (WTP) but also the potential errors/biases that prevent their true WTP from being observed. Objectives We propose a new elicitation mechanism, the circular payment card (CPC), and show that it helps overcome the drawbacks of the standard payment card (PC) format. It uses a visual pie chart representation without start or end points: respondents spin the circular card in any direction until they find the section that best matches their true WTP.
We performed a contingent valuation survey regarding a mandatory health insurance scheme in Tunisia, a middle-income country. Respondents were randomly allocated into one of three subgroups and their WTP was elicited using one of three formats: open-ended (OE), standard PC and the new CPC. We compared the elicited WTP. Results We found significant differences in unconditional and conditional analyses. Our empirical results consistently indicated that the OE and standard PC formats led to significantly lower WTP than the CPC format.
Overall, our results are encouraging and suggest CPC could be an effective alternative format to elicit ‘true’ WTP.
Dans le secteur des transports, les émissions de gaz à effet de serre (GES) et de polluants atmosphériques locaux (PAL) sont analysées de manière indépendante non seulement lors de la fixation des normes d’émissions, mais également dans l’analyse économique. Puisqu’elles ont la même origine (le pétrole), nous proposons d’étudier les conséquences de leur traitement joint sur le choix d’une politique de transport. Dans un premier temps, nous mettons en évidence les relations existant entre les impacts sanitaires et socio-économiques associés à ces deux sources de pollution, et rappelons les modalités de leur évaluation monétaire. Nous établissons ensuite que la politique de transport à privilégier, lorsque les GES et les PAL sont pris en compte conjointement avec leurs incertitudes et irréversibilités respectives, favorise la diminution du transport privé motorisé. Nous discutons enfin les implications pratiques de ce résultat en matière de choix sociétaux.
Public decision-makers commonly use health impact assessments (HIA) to quantify the impacts of various regulation policies. However, standard HIAs do not consider that chronic diseases (CDs) can be both caused and exacerbated by a common factor, and generally focus on exacerbations. As an illustration, exposure to near road traffic-related pollution (NRTP) may affect the onset of CDs, and general ambient or urban background air pollution (BP) may exacerbate these CDs. We propose a comprehensive HIA that explicitly accounts for both the acute effects and the long-term effects, making it possible to compute the overall burden of disease attributable to air pollution. A case study applies the two HIA methods to two CDs—asthma in children and coronary heart disease (CHD) in adults over 65—for ten European cities, totaling 1.89 million 0–17-year-old children and 1.85 million adults aged 65 and over. We compare the current health effects with those that might, hypothetically, be obtained if exposure to NRTP was equally low for those living close to busy roads as it is for those living farther away, and if annual mean concentrations of both PM10 and NO2—taken as markers of general urban air pollution—were no higher than 20 μg/m3. Returning an assessment of € 0.55 million (95 % CI 0–0.95), the HIA based on acute effects alone accounts for only about 6.2 % of the annual hospitalization burden computed with the comprehensive method [€ 8.81 million (95 % CI 3–14.4)], and for about 0.15 % of the overall economic burden of air pollution-related CDs [€ 370 million (95 % CI 106–592)]. Morbidity effects thus impact the health system more directly and strongly than previously believed. These findings may clarify the full extent of benefits from any public health or environmental policy involving CDs due to and exacerbated by a common factor.