Frédéric Aprahamian

Chercheur ,  Université de Toulon

Économétrie, finance et méthodes mathématiques
Aprahamian
Statut
Maître de conférences
Domaine(s) de recherche
Économie comportementale et expérimentale, Économétrie, Économie de l'environnement
Thèse
1991, Aix-Marseille Université
Contact
frederic.aprahamian[at]univ-amu.fr
+33(0)4 13 55 25 22
Adresse

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

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.
Publication HAL Google Scholar
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
Publication HAL Google Scholar
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
Publication HAL Google Scholar