Abstract. It has been shown that living in risky environments, as well as having a risky occupation, can mod- erate risk-tolerance. Despite the involvement of dopamine in the expectation of reward described by neurobiologists, a GWAS study was not able to demonstrate a genetic contribution of genes involved in the dopaminergic pathway in risk attitudes and gene candidate studies gave contrasting results. We test the possibility that a genetic effect of the DRD4-7R allele in risk-taking behavior could be modulated by environmental factors. We show that the increase in risk-tolerance due to the 7R allele is independent of the environmental risk in two populations in Northern Senegal, one of which is exposed to a very high risk due to dangerous fishing.

Abstract. Women are under-represented in top positions, such as in business or in politics. Traditional explanations, like differences in productivity and discrimination, are now complemented by psychological explanations based on lab experiments. We provide the first attempt to assess the comparative importance of psychological and traditional explanations in a natural field experiment, namely chess competitions. Controlling for discrimination and productivity, we find that women are suffering a systematic handicap when playing against men. This "psychological" effect is further amplified through the tournament structure, preventing women from reaching top positions in the chess hierarchy. The effect is only marginally smaller when we consider the most experienced individuals or the most women-friendly countries. 

Abstract. This paper analyzes within-session test/retest data from four different tasks used to elicit risk attitudes. Maximum-likelihood and non-parametric estimations on 16 datasets reveal that, irrespective of the task, measurement error accounts for approximately 50% of the variance of the observed variable capturing risk attitudes. The consequences of this large noise element are evaluated by means of simulations. First, as predicted by theory, the coefficient on the risk measure in univariate OLS regressions is attenuated to approximately half of its true value, irrespective of the sample size. Second, the risk- attitude measure may spuriously appear to be insignificant, especially in small samples. Unlike the measurement error arising from within-individual variability, rounding has little influence on significance and biases. In the last part, we show that instrumental-variable estimation and the ORIV method, developed by Gillen, Snowberg, and Yariv (2019), both of which require test/retest data, can eliminate the attenuation bias, but do not fully solve the insignificance problem in small samples. Increasing the number of observations to N=500 removes most of the insignificance issues.

Abstract. Two important lines of research have shaped our understanding of the ability of communities to engage in collective action. The first proposes ethnic division as a key determinant, with more ethnically-heterogeneous countries having worse economic performance and fewer public goods. The second focuses on social capital as a major determinant of the ability to engage in collective action. We expect trust among community members, a widely-used measure of social capital, to be an important and positive determinant of school quality. 

Early screening increases the likelihood of detecting cancer, thereby improving survival rates. National screening programs have been established in which eligible women receive a letter containing a voucher for a free screening. Even so, mammography use is often considered as remaining too low. We test four behavioral interventions in a large-scale randomized experiment involving 26,495 women. Our main assumption is that, due to biases in decision-making, women may be sensitive to the content and presentation of the invitation letter they receive. None of our treatments had any significant impact on mammography use. Sub-sample analysis suggests that this lack of a significant impact holds also for women invited for the first time and low-income women. 

Abstract. The ability to exert self-control is key to social insertion and professional success. An influential literature in psychology has developed the theory that self-control relies on a limited common resource, so that fatigue effects might carry over from one task to the next. However, the biological nature of the putative limited resource and the existence of carry-over effects have been matters of considerable controversy. Here, we targeted the activity of the lateral prefrontal cortex (LPFC) as a common substrate for cognitive control, and we prolonged the time scale of fatigue induction by an order of magnitude. Participants performed executive control tasks known to recruit the LPFC (working memory and task-switching) over more than 6 h (an approximate workday). Fatigue effects were probed regularly by measuring impulsivity in intertemporal choices, i.e., the propensity to favor immediate rewards, which has been found to increase under LPFC inhibition. Behavioral data showed that choice impulsivity increased in a group of participants who performed hard versions of executive tasks but not in control groups who performed easy versions or enjoyed some leisure time. Functional MRI data acquired at the start, middle, and end of the day confirmed that enhancement of choice impulsivity was related to a specific decrease in the activity of an LPFC region (in the left middle frontal gyrus) that was recruited by both executive and choice tasks. Our findings demonstrate a concept of focused neural fatigue that might be naturally induced in real-life situations and have important repercussions on economic decisions. 

Abstract. In this paper, we use an experimental design to compare the performance of elicitation rules for subjective beliefs. Contrary to previous works in which elicited beliefs are compared to an objective benchmark, we consider a purely subjective belief framework (confidence in one’s own performance in a cognitive task and a perceptual task). The performance of different elicitation rules is assessed according to the accuracy of stated beliefs in predicting success. We measure this accuracy using two main factors: calibration and discrimination. For each of them, we propose two statistical indexes and we compare the rules’ performances for each measurement. The matching probability method provides more accurate beliefs in terms of discrimination, while the quadratic scoring rule reduces overconfidence and the free rule, a simple rule with no incentives, which succeeds in eliciting accurate beliefs. Nevertheless, the matching probability appears to be the best mechanism for eliciting beliefs due to its performances in terms of calibration and discrimination, but also its ability to elicit consistent beliefs across measures and across tasks, as well as its empirical and theoretical properties. 

Abstract. We test for a causal role of social capital, as measured by self-reported trust, in determining access to basic health facilities in Sub-Saharan Africa. To skirt the reverse-causality problems between social capital and basic health, we rely on instrumental-variable (IV) estimates. A one standard-deviation increase in trust is predicted to lead to a 0.22 standard-deviation fall in doctor absenteeism, a 0.31 standard-deviation fall in waiting time and a 0.30 standard-deviation fall in bribes. As a robustness check, we also use a different database regarding a different health issue, access to clean water. We find that a one standard-deviation rise in trust leads to a 0.33 standard-deviation rise in access to clean water. The variety of public goods considered provides insights about the possible channels through which social capital is converted into health improvements. 

Abstract. Conventional economic theory assumes that agents should be consistent across decisions. However, it is often observed that experimental subjects fail to report consistent preferences. So far, these inconsistencies are almost always examined singly. We thus wonder whether the more inconsistent individuals in one task are also more inconsistent in other tasks. We propose an experiment in which subjects are asked to report their preferences over risky bets so as to obtain, for each subject, three measures of inconsistencies: classical preference reversals, framing effects and preference instability. In line with previous experimental findings, subjects are largely inconsistent according to each of these three measures and there are considerable individual differences. The main result is that we find no correlation among these three measures of inconsistency. 

Abstract. A major challenge for decision theory is to account for the instability of expressed preferences across time and context. Such variability could arise from specific properties of the brain system used to assign subjective values. Growing evidence has identified the ventromedial prefrontal cortex (VMPFC) as a key node of the human brain valuation system. Here, we first replicate this observation with an fMRI study in humans showing that subjective values of painting pictures, as expressed in explicit pleasantness ratings, are specifically encoded in the VMPFC. We then establish a bridge with monkey electrophysiology, by comparing single-unit activity evoked by visual cues between the VMPFC and the orbitofrontal cortex. At the neural population level, expected reward magnitude was only encoded in the VMPFC, which also reflected subjective cue values, as expressed in Pavlovian appetitive responses. In addition, we demonstrate in both species that the additive effect of prestimulus activity on evoked activity has a significant impact on subjective values. In monkeys, the factor dominating prestimulus VMPFC activity was trial number, which likely indexed variations in internal dispositions related to fatigue or satiety. In humans, prestimulus VMPFC activity was externally manipulated through changes in the musical context, which induced a systematic bias in subjective values. Thus, the apparent stochasticity of preferences might relate to the VMPFC automatically aggregating the values of contextual features, which would bias subsequent valuation because of temporal autocorrelation in neural activity. 

Abstract. When it comes to interpreting others' behaviour, we almost irrepressibly engage in the attribution of mental states (beliefs, emotions…). Such "mentalizing" can become very sophisticated, eventually endowing us with highly adaptive skills such as convincing, teaching or deceiving. Here, sophistication can be captured in terms of the depth of our recursive beliefs, as in "I think that you think that I think…" In this work, we test whether such sophisticated recursive beliefs subtend learning in the context of social interaction. We asked participants to play repeated games against artificial (Bayesian) mentalizing agents, which differ in their sophistication. Critically, we made people believe either that they were playing against each other, or that they were gambling like in a casino. Although both framings are similarly deceiving, participants win against the artificial (sophisticated) mentalizing agents in the social framing of the task, and lose in the non-social framing. Moreover, we find that participants' choice sequences are best explained by sophisticated mentalizing Bayesian learning models only in the social framing. This study is the first demonstration of the added-value of mentalizing on learning in the context of repeated social interactions. Importantly, our results show that we would not be able to decipher intentional behaviour without a priori attributing mental states to others. 

Abstract. Theory of Mind (ToM) is the ability to attribute mental states (e.g., beliefs and desires) to other people in order to understand and predict their behaviour. If others are rewarded to compete or cooperate with you, then what they will do depends upon what they believe about you. This is the reason why social interaction induces recursive ToM, of the sort “I think that you think that I think, etc.”. Critically, recursion is the common notion behind the definition of sophistication of human language, strategic thinking in games, and, arguably, ToM. Although sophisticated ToM is believed to have high adaptive fitness, broad experimental evidence from behavioural economics, experimental psychology and linguistics point towards limited recursivity in representing other’s beliefs. In this work, we test whether such apparent limitation may not in fact be proven to be adaptive, i.e. optimal in an evolutionary sense. First, we propose a meta-Bayesian approach that can predict the behaviour of ToM sophistication phenotypes who engage in social interactions. Second, we measure their adaptive fitness using evolutionary game theory. Our main contribution is to show that one does not have to appeal to biological costs to explain our limited ToM sophistication. In fact, the evolutionary cost/benefit ratio of ToM sophistication is non trivial. This is partly because an informational cost prevents highly sophisticated ToM phenotypes to fully exploit less sophisticated ones (in a competitive context). In addition, cooperation surprisingly favours lower levels of ToM sophistication. Taken together, these quantitative corollaries of the “social Bayesian brain” hypothesis provide an evolutionary account for both the limitation of ToM sophistication in humans as well as the persistence of low ToM sophistication levels. 

Abstract. This paper tests whether individual perceptions of markets as good or bad for a public good is correlated with the propensity to report gaps in willingness to pay and willingness to accept revealed within an incentive compatible mechanism. Identifying people based on a notion of market affinity, we find a substantial part of the gap can be explained by controlling for some variables that were not controlled for before. This result suggests the valuation gap for public goods can be reduced through well-defined variables. 

Abstract.  Spatial models of voting have dominated mathematical political theory since the seminal work of Downs. The Downsian model assumes that each elector votes on the basis of his utility function which depends only on the distance between his preferred policy platform and the ones proposed by candidates. A succession of papers introduces valence issues into the model, i.e., candidates’ characteristics which are independent of the platforms they propose. So far, little is known about which of the existing utility functions used in valence models is the most empirically founded. Using a large survey run prior to the 2007 French presidential election, we evaluate and compare several spatial voting models with valence. Existing models perform poorly in fitting the data. However, strong empirical regularities emerge. This leads us to a new model of valence that we call the intensity valence model. This new model makes sense theoretically and is grounded empirically. 

Abstract. To understand how decisions to invest in stocks are taken, economists need to elicit expectations regarding risk—return tradeoff. One of the few surveys which has elicited such expectations is the Survey of Economic Expectations in 1999—2001. Using the data from this survey, Dominitz and Manski find considerable heterogeneity across respondents that cannot be explained by simple models of expectations formation. Adapting a principle of dual reasoning borrowed from Kahneman, this paper classifies respondents according to their sensitivity to some pathologies. We find a substantial amount of unobserved heterogeneity between the least and the most sensitive respondents. We then sketch a model of expectations formation. 

Abstract. Simple exchange experiments have revealed that participants trade their endowment less frequently than standard demand theory would predict. List (2003a) found that the most experienced dealers acting in a well functioning market are not subject to this exchange asymmetry, suggesting that a significant amount of market experience is required to overcome it. To understand this market-experience effect, we introduce a distinction between two types of uncertainty—choice uncertainty and trade uncertainty—both of which could lead to exchange asymmetry. We conjecture that trade uncertainty is most important for exchange asymmetry. To test this conjecture, we design an experiment where the two treatments impact differently on trade uncertainty, while controlling for choice uncertainty. Supporting our conjecture, we find that “forcing” subjects to give away their endowment in a series of exchanges eliminates exchange asymmetry in a subsequent test. We discuss why markets might not provide sufficient incentives for learning to overcome exchange asymmetry.

Abstract. On October 12th, 2009 Elinor Ostrom received the Nobel Prize in Economics for her analysis of the commons. This article presents a survey of her work. We shall begin by redrawing the academic route of Ostrom. In the second part, we show how she successively used various methods of investigation throughout a route which leaves the meticulous study of multiple concrete situations to evolve towards the design of public policies for big international bodies. The conclusion describes the implications she draws from her work so as to contribute to a renewal of rational choice theory. 

Abstract. Miscalibration can be defined as the fact that people think that their knowledge is more precise than it actually is. In a typical miscalibration experiment, subjects are asked to provide subjective confidence intervals. A very robust finding is that subjects provide too narrow intervals at the 90% level. As a result a lot less than 90% of correct answers fall inside the 90% intervals provided. As miscalibration is linked with bad results on an experimental financial market (Biais et al., 2005) and entrepreneurial success is positively correlated with good calibration (Regner et al., 2006), it appears interesting to look for a way to cure or at least reduce miscalibration. Previous attempts to remove the miscalibration bias relied on extremely long and tedious procedures. Here, we design an experimental setting that provides several different incentives, in particular strong monetary incentives i.e. that make miscalibration costly. Our main result is that a thirty-minute training session has an effect on men's calibration but no effect on women's. 

Abstract. Surveys are sometimes viewed with suspicion when used to provide economic values, since they are sensitive to framing effects. However, the extent to which those effects may vary between individuals has received little attention. Are some individuals less sensitive to framing effects than others? We use the theory of social representation to assign to each individual a new variable to serve as a proxy for the individual’s sensitivity to framing effects. This allows to gather new and relevant information to limit the impact of framing effects. We examine two framing effects, starting-point bias and willingness-to-pay and willingness-to-accept divergence. 

Abstract. This paper explores a two-candidate spatial voting model, where one candidate has a valence advantage. Contrary to previous models, we introduce a multiplicative advantage, rather than an additive one. This takes into account the possible interaction between the quality of a candidate and his policy platform. This leads to a strikingly different model, in which all extreme voters support the favored candidate. 

Abstract. In this article, we propose a unified framework that accomodates many of the existing models for dichotomous choice contingent valuation with follow-up and allows to discriminate between them by simple parametric tests of hypothese. Our empirical results show that the Range model, developped in Flachaire and Hollard [2007], outperforms other standard models and confirms that, when uncertain, respondents tend to accept proposed bids. Dans cet article, nous proposons un cadre unifié permettant de tester de nombreux modèles à choix discrets existants en évaluation contingente. Une application montre que le modèle développé dans Flachaire et Hollard [2007] est le plus performant. Nos résultats empiriques confirment le fait que les individus ont tendance à accepter les offres proposées lorsqu'ils sont incertains. 

Abstract. 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. 

Abstract. Integrated assessment is rapidly developing in the scientific as well as policy community. Different methods, techniques and procedures (i.e., tools) are used in these assessments. Often, the choice for using certain tools in an assessment is not well founded. This paper presents a framework that scientifically underpins the role of, and thus choice for, tools within an integrated assessment. The framework identifies four phases in an integrated assessment, which are derived from the complementarities between various forms of integrated assessments. Tasks have to be done within each of the four phases. Seven types of tools with similar characteristics are matched to those tasks. The tool framework is a theoretical construct, developed whilst keeping in mind perceptions and suggestions from eventual users. It is a first step in the development of an overarching framework for finding appropriate tools for different tasks in an assessment, and justifying the use of those tools. 

Abstract. Samuel Bowles, the author of 'Microeconomics: Behavior, Institutions and Evolution, focuses on realism and economic behavior in microeconomics. He has also stressed on the Walrassian approach, which represents economic behavior as the solution to a constrained optimization problem faced by fully informed individuals in a institution-free environment. Bowles has stated that behavioral economics has been included in the Walrassian approach as marginal variation. He has also proposed a new approach to behavioral economics in microeconomics. He suggests that it is possible to introduce a new approach in microeconomics due to developments made in economic theory. The author also proposes to contribute to a new social science, which is not limited to studying individual behavior in a market environment. 

Abstract. In this paper, we study starting-point bias in double-bounded contingent valuation surveys. This phenomenon arises in applications that use multiple valuation questions. Indeed, response to follow-up valuation questions may be influenced by the bid proposed in the initial valuation question. Previous researches have been conducted in order to control for such an effect. However, they find that efficiency gains are lost when we control for undesirable response effects, relative to a single dichotomous choice question. Contrary to these results, we propose a way to control for starting-point bias in double-bounded questions with gains in efficiency. 

Abstract. We develop and implement a collocation method to solve for an equilibrium in the dynamic legislative bargaining game of Duggan and Kalandrakis (2008). We formulate the collocation equations in a quasi-discrete version of the model, and we show that the collocation equations are locally Lipchitz continuous and directionally differentiable. In numerical experiments, we successfully implement a globally convergent variant of Broyden's method on a preconditioned version of the collocation equations, and the method economizes on computation cost by more than 50% compared to the value iteration method. We rely on a continuity property of the equilibrium set to obtain increasingly precise approximations of solutions to the continuum model. We showcase these techniques with an illustration of the dynamic core convergence theorem of Duggan and Kalandrakis (2008) in a nine-player, two-dimensional model with negative quadratic preferences. 

Abstract. In this note we prove a McGarvey theorem for the family of Separable Tournaments. This family arises in the analysis of Logrolling and Vote Trading in Committees. 

Abstract. Le 9 octobre 2017, Richard H. Thaler a reçu le Prix de la Banque de Suède en sciences  économiques en mémoire d’Alfred Nobel pour ses travaux en économie comportementale. Cet article présente ses principales contributions, à savoir l'établissement d’une liste d’anomalies du comportement rationnel, les fondements d’un modèle quasi-rationnel inspiré de la psychologie et, finalement, l’approche des politiques publiques connue sous le nom de Nudge. Pour conclure, nous revenons de manière plus subjective sur les apports de Thaler en économie, et spéculons sur un avenir possible de l'économie comportementale.

Abstract. Public economics proposed various models that intend to determine the optimal provision of public goods based on individual preferences. To provide decision makers with empirical recommendations, economists thus need to elicit individual preferences, and more precisely the marginal rate of substitution between private and public goods. Contingent valuation has proved a useful, and successful, tool to gather information on individual preferences. However, contingent valuation has been proved sensitive to various biases. In other words, variables that are not expected to have any influence do so in practice. In this paper, we propose a methodology, based on social psychology, which allows the identification of individuals that are proved immune to biases. This allows designing more powerful, bias free, estimation of individual preferences. Two distinct applications are provided. 

Abstract. Leading researchers, such as Elster or Hirschman, have put forward the notion of deliberation. They argue of the major importance of deliberation in understanding democracy. However, economic theory doesn’t have much to say on deliberation. We argue that this weakness is inherent with the way of conceiving public decision making in economics. In a second part, we review the small literature existing on deliberation in economics 

Abstract. Il s'agit d'une exploration des limites de l'approche quantitative dans l'analyse du territoire, qui ne peut se limiter à une analyse formelle. La démarche analytique se présente à deux niveaux distincts : constitution d'une base de donnée à l'échelle du département des Bouches du Rhône, liée à système d'information géographique (SIG), développement d'une analyse statistique destinée à une première investigation des logiques d'évolution territoriale. Le foncier est considéré comme un objet médian d'analyse. Il peut fournir un support à des discussions entre les différentes disciplines s'intéressant à la question du territoire. Les analyses statistiques présentées permettent de relativiser l'idée de l'homogénéité du marché foncier. Les analyses menées font apparaître deux niveaux de structuration dans la répartition spatiale des zones de prix: un premier niveau d'ordre départemental en termes de proximité à certains pôles d'activités, et un niveau de structuration communal fortement orienté par la politique d'aménagement de la commune et par un certain nombre de caractéristiques paysagères ou sociales des quartiers. 

Abstract. Early screening increases the likelihood of detecting cancer, thereby improving survival rates. National screening programs have been established in which eligible women receive a letter containing a voucher for a free screening. Even so, mammography use is often considered as remaining too low. We test four behavioral interventions in a large-scale randomized experiment involving 26,495 women. Our main assumption is that, due to biases in decision-making, women may be sensitive to the content and presentation of the invitation letter they receive. None of our treatments had any significant impact on mammography use. Sub-sample analysis suggests that this lack of a significant impact holds also for women invited for the first time and low-income women.