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International audience; Gouvernement mixte et activités commerciales traversent l’œuvre de Gabriel Bonnot de Mably. Favorable au développement de l’agriculture, de l’industrie et du libre-échange, il reconnait cependant les effets corrupteurs que génèrent les sociétés commerciales. Il considère alors le système de contre forces comme le meilleur moyen de réconcilier les intérêts privés pour faire émerger un intérêt commun. Son programme de réforme constitutionnel pour la Pologne en est un bon exemple.

The crisis of 2007-08 called for a renewal of banking regulation that took the shape of a shift toward macroprudential policy. However, a comprehensive assessment of the current state of financial regulation reveals that this shift is incomplete. In particular, the notion of risk that lies at the heart of the Basel framework is still blind to extreme events. Climate risk and pandemic risk fall into this category. The purpose of this article is twofold. On the one hand, we point out why current banking regulation is not adequate to face risks whose origin is grounded outside financial markets – as is the case for both the pandemic and the climate risks –; on the other hand, we offer avenues for reforming macroprudential regulation in a way that would allow to take those risks into account.

We examine the educative role played by parents in social norm transmission. Using a field experiment, we study whether parents enforce and comply more with norms when their children are present compared to when they are not. We compare similar parents when or after they drop off or pick up their children at school. We find that parents accompanying children, in contrast to parents alone, are more likely to punish norm violators and to provide help to strangers when there is no violation. They also tend to substitute more direct punishment with withholding help as a means of indirect punishment.

International audience

There is an assumption that the provision of local public services by intermunicipal jurisdictions is more efficient due to the opportunities to exploit economies of scale and reduce tax competition between municipalities. We use the staggered adoption of inter-municipal cooperation in France during the years 2002 to 2019 and show that cooperation increased local spending and tax revenues substantially during that period. Our original data on the specific missions and fiscal regimes of communities allow us to distinguish between the effects of transfer of mission(s) to the community and tax harmonization on the provision of public services. Our analysis confirms that tax harmonization has resulted in increased local public spending due to higher state grants. However, with the exception of water, we found no evidence of a negative effect on spending from the joint provision of public goods and in the case of public transport we found a sizable increase in spending as a result of its transfer to the community. Overall, we can conclude that scale economies if any are clearly dominated by a “zoo” effect i.e. extension of provision of new public services to small and formerly isolated municipalities and by a tax harmonisation effect.

Natural disasters and related prevention policies can affect voter decisions. In this study, we analyze how the occurrence of natural disasters changes voters' behavior at municipal elections and how prevention policies can mitigate the impact of such catastrophic events on budget accounts and might potentially be rewarded by citizens in upcoming elections. We exploit original data on French municipalities where incumbents sought reelection between 2008 and 2020. To estimate the probability of re-election at the municipal level in the event of a natural disaster we apply a Heckman model based strategy to avoid selection bias. We find that the occurrence of natural disasters significantly decreases the chances of reelection of incumbent mayors. However, although we show that natural hazard prevention plans significantly mitigate the impact of catastrophic events on budget accounts, citizens do not reward such prevention policies in upcoming elections. We confirm the hypothesis of myopia: voters reward incumbents for delivering investment spending or decreasing debt but not for investing in spending on disaster preparedness.

This paper disentangles the relationship between COVID-19 propagation and mobility. In a theoretical model allowing mobility to be endogenously determined by the COVID-19 prevalence rate, we show that an exogenous epidemic shock has an immediate effect on mobility whereas an exogenous mobility shock influences epidemic variables with a delay. In the long run, exogenous disease contagiousness and mobility jointly shape epidemiological outcomes. The short-run theoretical result allows us to recover, empirically, the causal impacts of mobility and COVID-19 hospitalisations on each other in France. We find that hospitalisations are highly sensitive to mobility whereas mobility is little influenced by hospitalisations. In France, it seems therefore that voluntary social distancing would not have been effective to control the epidemic, in the absence of social distancing mandates.

International audience

Low insurance take-up in low-income populations is not easily explained by the standard single-period expected utility model of insurance that overlooks the relevance of time preference when liquidity is constrained. We design field survey instruments to elicit quasi-hyperbolic time preferences, as well as prospect theory risk preferences, and use them to examine whether time preferences explain health insurance behavior of low-income Filipinos. Consistent with theory, those with stronger parameterized time preference are less likely to insure and the partial association is most pronounced at low wealth where liquidity is most likely to be constrained. Among those with better understanding of insurance, lower take-up is also associated with present bias. We do not find that insurance is significantly associated with risk preferences.

We solve the nonlinear income tax program for rank-dependent social welfare functions, expressing the trade-off between size and inequality using the Gini and related families of positional indices. Absent bunching, ranks in the actual and optimal allocations are invariant. Exploiting this feature, we provide new, simple, and intuitive tax formulas for both the quasilinear and additive cases and new comparative static results. Our approach makes insights from optimal taxation more widely accessible. In some of our simulations the actual US tax policy is close to being optimal—except at the top, where optimal rates are much higher than in actuality. (JEL D31, D63, H21, H24, K34)

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International audience; We use an experimental asset market with eye-tracker measurements for a novel exploration of the cognitive validity of a classic heterogeneous trader taxonomy. Following a top-down approach, we assume that the patterns of attention and information acquisition are governed by one of the three trading strategies, either feedback, passive, or speculative. In line with our first hypothesis, speculators seek information about market expectations. Notwithstanding the two other hypotheses, feedback traders reveal patterns of attention and information acquisition that could ex ante be expected from passive traders, and vice versa.

Several recent papers introduce different mechanisms to explain why asset bubbles are observed in periods of larger growth. These papers share common assumptions, heterogeneity among traders and credit market imperfection , but differ in the role of the bubble, used to provide liquidities or as collateral in a borrowing constraint. In this paper, we introduce heterogeneous traders by considering an overlapping generations model with households living three periods. Young households cannot invest in capital, while adults have access to investment and face a borrowing constraint. Introducing bubbles in a quite general way, encompassing the different roles they have in the existing literature, we show that the bubble may enhance growth when the borrowing constraint is binding. More significantly, our results do not depend on the-liquidity or collateral-role attributed to the bubble. We finally extend our analysis to a stochas-tic bubble, which may burst with a positive probability. Because credit and bubble are no more perfectly substitutable assets, the liquidity and collateral roles of the bubble are not equivalent. Growth is larger when bubbles play the liquidity role, because the burst of a bubble used for liquidity is less damaging to agents who invest in capital.

A natural gas distribution network connects consumers to a source of gas. It is managed by a network operator, whose task incurs various costs, some of which may not be attributable to a particular consumer. Assuming that the operator wishes to recover these costs by charging for its services, the problem is then to determine how much each consumer should pay. In other words, how should these costs be allocated among consumers. In this paper, we address this problem and propose cost allocation rules that depend on the network and the demands of the consumers. To that end, we adopt a normative approach and oppose two principles: (i) the connection principle and (ii) the uniformity principle. The Connection rule is proposed in accordance with (i), while the Uniform rule is developed in line with (ii). It appears that (i) and (ii) are incompatible. To make a trade-off between these two principles, we propose the family of Mixed rules, which compromise between the Connection rule and the Uniform rule by mean of convex combinations. For each cost allocation rule, an axiomatic characterization is provided. Then, we show that the Connection rule coincides with the multi-choice Shapley value of a specific multi-choice game derived from the network and the demands of the consumers. Moreover, the Connection rule is in the Core of this specific multi-choice game. Similarly, we show that the Uniform rule coincides with the multi-choice Equal division value and the Mixed rules coincide with the multi-choice Egalitarian Shapley values.

International audience; We introduce a new family of values for TU-games with a priority structure, which both containsthe Priority value recently introduced by B´eal et al. (2022) and the Weighted Shapley values (Kalaiand Samet, 1987). Each value of this family is called a Weighted priority value and is constructedas follows. A strictly positive weight is associated with each agent and the agents are partiallyordered according to a binary relation. An agent is a priority agent with respect to a coalitionif it is maximal in this coalition with respect to the partial order. A Weighted priority valuedistributes the dividend of each coalition among the priority agents of this coalition in proportionto their weights. We provide an axiomatic characterization of the family of the Weighted Shapleyvalues without the additivity axiom. To this end, we borrow the Priority agent out axiom fromB´eal et al. (2022), which is used to axiomatize the Priority value. We also reuse, in our domain,the principle of Superweak differential marginality introduced by Casajus (2018) to axiomatizethe Positively weighted Shapley values (Shapley, 1953). We add a new axiom of Independence ofnull agent position which indicates that the position of a null agent in the partial order does notaffect the payoff of the other agents. Together with Efficiency, the above axioms characterize theWeighted Shapley values. We show that this axiomatic characterization holds on the subdomainwhere the partial order is structured by levels. This entails an alternative characterization of theWeighted Shapley values. Two alternative characterizations are obtained by replacing our principleof Superweak differential marginality by Additivity and invoking other axioms.

In the US, almost half of unemployment spells end through recall. In this paper, we show that the probability of being recalled is much higher among unemployment benefit recipients than non-recipients. We argue that a large part of the observed difference in recall shares is accounted for by the design of the unemployment insurance financing scheme characterized by an experience rating system. We develop a search and matching model with different unemployment insurance status, endogenous separations, recalls and new hires. We quantify what would have been the labor market under alternative financing scheme. In the absence of the experience rating, the hiring and separations would have been higher in the long run and more volatile. Experience rating system contributes significantly to the difference in recalls between the recipients and the non-recipients.

International audience; L’analyse du contrat menée par Hegel dans les Principes de la philosophie du droit permet d’éclairer le débat récent portant sur l’annulation de la dette publique détenue par la Banque centrale européenne. De fait, en soulignant le caractère abstrait du contrat lorsqu’il est envisagé indépendamment de tout ancrage politique, Hegel insiste sur l’impossibilité de penser l’ordre social comme reposant exclusivement sur la relation contractuelle. Cette dernière ne trouve, en effet, à s’actualiser que sur fond d’une totalité politique déjà constituée, c’est-à-dire l’État, qui, en conséquence, ne saurait relever de la rationalité abstraite propre au contrat. C’est donc un contresens que de considérer l’État comme un débiteur irrémédiablement tenu de se plier à ses engagements contractuels.

International audience; Prevention efforts, such as quitting smoking, flu vaccination, and exercising, are of crucial importance in health policy, but people tend to undertake too few of them. The main reason is that most prevention efforts only reduce but do not completely eliminate the risk of poor health. This makes it harder for people to assess the benefits of prevention, because they tend to misperceive and transform probabilities. In “When Risk Perception Gets in the Way: Probability Weighting and Underprevention,” Baillon et al. introduce psychological insights (probability weighting) in a model of optimal decision making and show that most people undertake too little prevention when the risk of poor health is between 10% and 80%. The paper discusses several policy measures to make people spend more on prevention.

Background Studies of the hospital volume-outcome relationship have highlighted that a greater volume activity improves patient outcomes. While this finding has been known for years, most studies to date have failed to delve into what underlies this relationship. Objective This study aimed to shed light on the basis of the hospital volume effect on patient outcomes by comparing treatment modalities for epithelial ovarian carcinoma patients. Data An exhaustive dataset of 355 patients in first-line treatment for Epithelial Ovarian Carcinoma (EOC) in 2012 in three regions of France was used. These regions account for 15% of the metropolitan French population. Methods In the presence of endogeneity induced by a reverse causality between hospital volume and patient outcomes, we used an instrumental variable approach. Hospital volume of activity was instrumented by the distance from patients’ homes to their hospital, the population density, and the median net income of patient municipalities. Results Based on our parameter estimates, we found that the rate of complete tumor resection would increase by 15.5 percentage points with centralized care, and by 8.3 percentage points if treatment decisions were coordinated by high-volume centers compared to decentralized care. Conclusion As volume alone is an imperfect correlate of quality, policy-makers need to know what volume is a proxy for in order to devise volume-based policies.

International audience

International audience; Under welfarism, assertions such as “this social state is better than an alternative” or “this policy should be enacted” are based on the assumption that social welfare ultimately depends only on the well-being of individuals. A normative analysis of welfarism seeks to provide a transparent description of the basis upon which welfarism makes its value judgments, which is equivalent to an investigation into its choice of a preferred notion of well-being. Such an investigation, this paper claims, can take two forms, which we should distinguish: the ethical analysis of welfarism is concerned with the appeal to a given ethical theory of well-being; and the technical analysis of welfarism concerns the specific measure of individual utility that in practice is used to measure social welfare. Reviewing a series of claims which bear on how these two versions of welfarism are articulated (the standard, proxy, evidential and tension claims), the paper explores the differences between the ethical and technical approaches in the normative interpretation of welfarist assertions.; Dans le cadre d’étude welfariste, des affirmations telles que « cet état social est meilleur que tel autre état social » ou « cette politique devrait être promulguée » reposent sur l’hypothèse que le bien-être social ne dépend que du bien-être des individus et de rien d’autre. Une analyse normative du welfarisme vise à fournir une description transparente des jugements de valeur impliqués dans ces évaluations et ces recommandations, ce qui revient à s’interroger en particulier sur la notion du bien-être qui a été retenue. Cette enquête normative peut prendre deux formes et cet article défend l’idée qu’il convient de les distinguer : l’analyse éthique du welfarisme concerne le recours à une théorie éthique donnée du bien-être ; et l’analyse technique du welfarisme concerne la mesure de l’utilité individuelle qui est utilisée en pratique pour mesurer ce bien-être social. L’article passe en revue successivement quatre points de vue types portant sur l’articulation de ces deux versions du welfarisme : le point de vue standard, de l’approximation, de la preuve et de la tension. En étudiant l’interprétation normative des affirmations welfaristes, il explore les différences qui émergent entre les approches éthique et technique.

Experimental studies of social dilemmas have shown that while the existence of a sanctioning institution improves cooperation within groups, it also has a detrimental impact on group earnings in the short-run. Could the introduction of pre-play threats to punish have enough of a beneficial impact on cooperation, while not incurring the cost associated with actual punishment, so that they increase overall welfare ? We report an experiment in which players can issue non-binding threats to punish others based on their contribution levels to a public good. After observing others' actual contributions, they choose their actual punishment level. We find that threats increase the level of contributions significantly. Efficiency is improved, but only in the long run. However, the possibility of sanctioning differences between threatened and actual punishment leads to lower threats, cooperation and welfare, restoring them to levels equal to or below the levels attained in the absence of threats.

Throughout his life, Mably defends the soft trade principles. By adopting a new interpretation grid (science of commerce), his criticism of commercial civilization can be reconsidered. He is in line with the thinking movement of the years 1750-1760, which made agriculture the foundation of economic activity. To ensure the development of the agricultural sector, the free circulation of goods within the kingdom must be allowed and foreign trade must be encouraged as it provides additional outlets for domestic production. Domestic and foreign trade are therefore two complementary and mutually supportive activities. Mably also promotes trade and industry in ‘useful’ goods against the luxury of a minority. The economic development project for Poland therefore appears to be an attempt to move from theory to practice.

International audience; This article analyzes the effects of the acquisition of the Port of Piraeus by the Chinese shipping operator COSCO in July 2016 on the organization of container traffic in Europe. Using real-time container ship positions provided by vessel tracking systems between 2015 and 2019, we study the impact of the privatization of the Greek port on its attractiveness and on that of competing ports for the ships of the various operators, and more particularly of COSCO. Difference-in-difference estimates suggest that the number of container ship calls to the Port of Piraeus has increased following its privatization, but that this increase in attractiveness corresponds mainly to vessels operated by COSCO with a capacity of more than 3000 twenty-foot equivalent units, and in particular to the largest of them. We do not identify any crowding out effect between operators in Piraeus: the use of Piraeus by the vessels of other operators remains relatively unchanged. The privatization of Piraeus seems to have imposed the Greek port as COSCO's transhipment hub for the European market without this being to the detriment of ports in any other particular European area.

Telemedicine is often put forward as a solution to medical deserts. Recently, telemedicine has allowed to limit physical contacts during a pandemic. We analyze within a theoretical model the setting of physicians' fees in the presence of distant medicine and public health insurance, as well as the resulting patients' surplus, access and public expenses. Concretely, we consider that distant medicine is provided either by the same physician as in-person medicine or by another one specialized in distant medicine. We compare the outcomes of these two market structures with each other and with a benchmark monopoly with no distant medicine. This comparison allows to discuss the effects of a recent French reform concerning insurance reimbursements for distant medicine, as well as those of cross-border high-quality remote health services.

International audience; Considering optimal non-linear income tax problems when the social welfare function only depends on ranks as in Yaari (Econometrica 55(1):95–115, 1987) and weights agreeing with the Lorenz quasi-ordering, we extend the analysis of Simula and Trannoy (Am Econ J Econ Policy, 2021) in two directions. First, we establish conditions under which bunching does not occur in the social optimum. We find a sufficient condition on individual preferences, which appears as a reinforcement of the Spence-Mirrlees condition. In particular, the marginal dis-utility of gross income should be convex, but less convex the higher the productivity. We also show that, for all productivity distributions with a log-concave survival function, bunching is precluded under the maximin, Gini, and “illfare-ranked single-series Ginis”. Second, we turn to a discrete population setting, and provide an “ABC” formula for optimal marginal tax rates, which is related to those for a continuum of types found in Simula and Trannoy (2021), but remain essentially distinct.

International audience; Several physical features influence the perception of how cooperative a potential partner is. While previous work focused on face and voice, it remains unknown whether body odours influence judgements of cooperativeness and if odour-based judgements are accurate. Here, we first collected axillary odours of cooperative and uncooperative male donors through a public good game and used them as olfactory stimuli in a series of tasks examining whether and how they influence cooperative decision-making in an incentivized economic game and ratings of cooperativeness. Our results show that having access to the donor's body odours provided a strategic advantage to women during economic decisions (but not to men): with age, women were more likely to cooperate with cooperative men and to avoid interacting with uncooperative men. Ratings of cooperativeness were nonetheless unrelated to the donors’ actual cooperativeness. Finally, while men with masculine and intense body odours were judged less cooperative, we found no evidence that donors’ actual cooperativeness was associated with less masculine or less intense body odour. Overall, our findings suggest that, as faces and voices, body odours influence perceived cooperativeness and might be used accurately and in a non-aware manner as olfactory cues of cooperativeness, at least by women.

We study cheating as a collective-risk social dilemma in a group setting in which individuals are asked to report their actual outcomes. Misreporting their outcomes increases the individual's earnings but when the sum of claims in the group reaches a certain threshold, a risk of collective sanction affects all the group members, regardless of their individual behavior. Because of the pursuit of selfish interest and a lack of coordination with other group members, the vast majority of individuals eventually earn less than the reservation payoff from honest reporting in the group. Over time, most groups are trapped in a "Tragedy of Dishonesty", despite the presence of moral costs of lying. The risk of collective sanction is triggered less frequently in small groups than in large ones, while priming a collectivist mindset has little effect on lying.

International audience; Le CASD est une « bulle sécurisée », c’est-à-dire une infrastructure de stockage et de traitement des données oùdes données confidentielles sont sanctuarisées. 477 sources de données y sont disponibles, avec entre autresdes données de l’INSEE, des ministères de la Justice, de l’Éducation nationale, de l’Agriculture et de l’alimentation. Une équipe dédiée gère l’accès des utilisateurs.Cette intervention aura pour but de présenter les modalités d’utilisation du CASD, depuis la demande d’accès jusqu’à l’exportation des résultats d’analyse, sur la base d’une expérience d’utilisation pour des recherches en économie.

International audience; We study the impact of competition on morals using a dynamic variant of the die-under-the-cup task. Players can repeatedly misreport the outputs of consecutive die rolls to earn more money, either under an individual piece-rate pay scheme or in a two-player tournament. In this dynamic setting, we disentangle the effect of the incentive scheme and the effect of information provision about one's relative performance, by comparing settings with continuous vs. final ex post feedback on the counterpart's reported outcome. We find that individuals lie more under competitive rather than non-competitive incentive schemes, but only if both players can cheat in the tournament. Continuous feedback on the counterpart's reports does not increase cheating in the tournament, while it does under the piece-rate scheme. These findings shed light on the effects that different competition and information policies have on morals in occupational settings.

Surveys typically use hypothetical questions to measure subjective and unverifiable concepts like happiness and quality of life. We test whether this is problematic using a large survey experiment on health and subjective well-being. We use Prelec’s Bayesian truth serum to incentivize the experiment and defaults to introduce biases in responses. Without defaults, the data quality was good and incentives had no impact. With defaults, incentives reduced default biases in the subjective well-being questions by inducing participants to spend more effort. Incentives had no impact on the health questions regardless of whether defaults were used. This research was made possible by a Vidi grant (452-13-013) of the Netherlands Organization for Scientific Research (NWO).

International audience; This article quantifies the effects of increasing global geopolitical uncertainty on the size of migration flows to Western Europe. Uncertainty is measured by the number of victims of terrorist attacks worldwide. The effect on migration flows is quantified through the estimation of vector autoregressive models on a panel of 15 European countries and on France, thanks to an original migration dataset. The estimations suggest that the flows of permanent migrants are generally reduced by global terrorism. In particular, the increase in uncertainty that followed the attacks of September 11, 2001, caused an 8% drop in flows to Europe and a 19% drop in flows to France. The effect of global uncertainty on the flow of asylum seekers depends on the country: on average in Europe, asylum applications increase with terrorism, but for France, they decrease with terrorism. This difference can be explained by the geographical position and border control policies of France.

International audience

International audience; This paper is a book review of Matthew Adler's bool "Measuring Social Welfare: An Introduction", published at OUP in 2019. The book is an introduction to the social welfare function approach, meant to assess social welfare and help public decision making, as a comprehensive and welcome alternative to cost-benefit analysis. The review first provides a number of references to situate the contribution of the book in the literature. Secondly, it insists on the fact that the social welfare approach is able to express transparently normative criteria, by contrast with CBA. Thirdly, it highlights that, after the focus on efficiency, the book well illustrates how to incorporate wider distributive criteria; it also enables to encompass different kinds of public policies beyond fiscal redistribution. Fourthly, it regrets that the book does not yet illustrate how to cope with the diversity of values and relevant information beyond utility and income, however introduced as theoretically possible.

This paper provides the first axiomatic characterization of a class of certification methods, dubbed proportional threshold methods, that builds on consistency properties across populations and profiles of binary opinions. We then compare proportional threshold methods with the approval voting method. We formally outline the similarities and differences of these two collective decision processes and provide an axiomatic characterization of the approval voting method that, perhaps surprisingly, is closely related to the one of the proportional threshold methods.

BackgroundThe spread of infectious diseases can be modeled using deterministic models assuming a continuous population or stochastic models assuming a discrete population. A stochastic model can be approximated by its deterministic counterpart under some conditions, however deterministic models are unable to captures effects pertaining to the discrete nature of populations, for instance epidemic extinction. We look into the choice of a model – deterministic or stochastic – from the perspective of decision making. We are interested in the influence of parameter uncertainties and of the quality of the estimates used to inform decisions.MethodWe consider an emerging disease in a closed population whose spread can be modeled by a stochastic SIR model or its deterministic version. Our objective is to minimize the cumulative number of symptomatic infected-days over the course of the epidemic by picking a vaccination policy out of three available options. We consider four decision making scenarios: based on the stochastic model or the deterministic model, and informed or under parameter uncertainty. We also consider different sample sizes covering parameter draws, stochastic model runs, or both depending on the scenario. We estimate the average performance of decision making in each scenario and for each sample size.ResultsThe model used for decision making has an influence on the picked policies. The best achievable performance is obtained with the stochastic model, knowing parameter values, and for a large sample size. For small sample sizes, the deterministic model can outperform the stochastic model due to stochastic effects, both in the informed and the uninformed cases. Starting with the deterministic model under uncertainty, resolving uncertainties brings more benefit than switching to the stochastic model in our example.ConclusionThis article illustrates the interplay between the choice of a type of model, parameter uncertainties, and sample sizes. It points to issues to be carefully considered when attempting to optimize a stochastic model.

International audience

International audience

International audience; Dilemmas related to the use of environmental resources concern diverse populations at local or global scales. Frequently, individuals are unable to visualize the consequences of their actions, where they belong in the decision-making line, and have no information about past choices or the time horizon. We design a new one-shot extraction game to capture these dynamic decisions. We present results from a nationwide common pool resource experiment, conducted simultaneously in eleven French cities, involving a total of 2813 participants. We examine, for the first time, the simultaneous impact of several variables on the amount of resource extracted: the local vs. the national scale of the resource, the size of the group (small vs. big), the low vs. high recovery rate of the resource, and the available information. We show that individuals significantly reduce extraction levels in local as compared to national level dilemmas and that providing recommendations on sustainable extraction amounts significantly improves the sustainability of the resource. Overall, women extract significantly less, but care more about preserving the local resource; older participants extract significantly more resources but extract less from the national resource. Our experiment also fulfills a science popularization pedagogical aim, which we discuss..

In more and more situations, artificially intelligent algorithms have to model humans’ (social) preferences on whose behalf they increasingly make decisions. They can learn these preferences through the repeated observation of human behavior in social encounters. In such a context, do individuals adjust the selfishness or prosociality of their behavior when it is common knowledge that their actions produce various externalities through the training of an algorithm? In an online experiment, we let participants’ choices in dictator games train an algorithm. Thereby, they create an externality on future decision making of an intelligent system that affects future participants. We show that individuals who are aware of the consequences of their training on the pay- offs of a future generation behave more prosocially, but only when they bear the risk of being harmed themselves by future algorithmic choices. In that case, the externality of artificially intelligence training induces a significantly higher share of egalitarian decisions in the present.

This paper studies how predation strategies can affect the sustainability of collusion. We demonstrate that in the presence of few competitors collusion may be sustained at equilibrium for intermediate discount factors. In such instances predation implies that punishment strategies will yield low subgame perfect payoffs, thereby making collusion easier to sustain. For low discount factors collusion is not sustainable because of the high incentives to deviate to Cournot-Nash strategies. Moreover, for high discount factors it is always optimal to predate colluding firms, thus contrasting with much of the earlier literature showing that collusion is only achievable by sufficiently patient firms.

International audience; The old-age security motive for fertility postulates that people’s needs for old-age support raise the demand for children. We exploit the extension of social pensions in Namibia during the 1990s to provide a quasi-experimental quantification of this widespread idea. The reform eliminated inequalities in pension coverage and benefits across regions and ethnic groups. Combining differences in pre-reform pensions and differences in exposure across cohorts, we show that pensions substantially reduce fertility, especially in late reproductive life. The results suggest that improving social protection for the elderly could go a long way in fostering fertility decline in sub-Saharan Africa. (JEL H55, I38, J13, J14, O15)

International audience; Strategic uncertainty is the uncertainty that players face with respect to the purposeful behavior of other players in an interactive decision situation. Our paper develops a new method for measuring strategic-uncertainty attitudes and distinguishing them from risk and ambiguity attitudes. We vary the source of uncertainty (whether strategic or not) across conditions in a ceteris paribus manner. We elicit certainty equivalents of participating in two strategic 2x2 games (a stag-hunt and a market-entry game) as well as certainty equivalents of related lotteries that yield the same possible payoffs with exogenously given probabilities (risk) and lotteries with unknown probabilities (ambiguity). We provide a structural model of uncertainty attitudes that allows us to measure a preference for or an aversion against the source of uncertainty, as well as optimism or pessimism regarding the desired outcome. We document systematic attitudes towards strategic uncertainty that vary across contexts. Under strategic complementarity [substitutability], the majority of participants tend to be pessimistic [optimistic] regarding the desired outcome. However, preferences for the source of uncertainty are distributed around zero.

International audience; Six chercheurs appellent les pouvoirs publics à tenir compte des acquis des sciences sociales pour mieux comprendre et anticiper les effets de leurs choix politiques sur les comportements des citoyens.

International audience

International audience

This paper analyzes the size of government spending multiplier in two policy mix cases: Active Monetary/Passive Fiscal policy (regime M) in the first instance and Passive Monetary/Active Fiscal policy (regime F), in the sense of Leeper (1991), in the second. I develop a New-Keynesian model where preferences are subject to external deep habits and where some households do not have access to financial markets. I show that these two specifications allow for the crowding in of private consumption in both regimes. However, the private investment falls in regime M while it rises in regime F as a response to a government spending shock. In addition, I show that the impact multiplier increases with the degree of deep habits in regime M, while it decreases in regime F. In this framework, in a low nominal interest rate environment, the government spending multiplier is not too large as vast studies show. However, I find that the global effectiveness of government spending is larger in regime F than in regime M, even though the impact multiplier is greater than unity in both regimes.

Recently a credibility crisis has taken hold across the social sciences, arguing that a component of Fischer (1935)'s tripod has not been fully embraced: replication. The importance of replications is not debatable scientifically, but researchers and journals' incentives are not sufficient to encourage replications. We analyze a novel, decentralized approach promoting replications through beneficial gains between scholars and editors. We highlight the trade-offs involved in seeking independent replications before submission to journals, and demonstrate the operation of this method via an investigation of the effects of Knightian uncertainty on cooperation in public goods games, a pervasive feature but largely unexplored in the literature.

The role of a gas distribution network is to connect consumers to a gas source. This network is managed by an operator, whose task incurs various costs. Some of these costs may not be attributable to a particular consumer.Assuming that the operator wishes to recover these costs by charging for its services, the problem is then how to share these costs among consumers.This thesis proposes solutions to this problem using multi-choice (cooperative) game theory.All the solutions proposed in this thesis are designed to take into account the gas demands of consumers.Furthermore, since certain ethical principles are desirable for a network operator with respect to how it bills consumers, some of our solutions are designed to satisfy these principles. These are: the independence of higher demands principle and the uniformity principle. Finally, some solutions also manage to take into account the different information provided by the distribution network.This thesis consists of seven chapters. Chapter 1 serves as an introduction. Chapter 2 introduces the notations and definitions necessary for a good understanding of the thesis. Chapters 3 to 6 contain the contributions of the thesis.Each of these contributions brings its own solutions.We axiomatically characterize each of them and discuss their relevance in the context of gas distribution. Finally, Chapter 7 concludes the thesis.; Le rôle d'un réseau de distribution de gaz est de connecter des consommateurs à une source de gaz. Ce réseau est géré par un opérateur, dont la tâche engendre divers coûts. Certains de ces coûts peuvent ne pas être imputables à un consommateur particulier.En supposant que l'opérateur souhaite recouvrir ces coûts en facturant ses services, le problème est alors de déterminer comment partager ces coûts entre les consommateurs.La présente thèse propose des solutions à ce problème en mobilisant la théorie des jeux (coopératifs) multi-choix.Toutes les solutions proposées dans cette thèse sont conçues pour prendre en compte les demandes en gaz des consommateurs.De plus, comme certains principes éthiques sont souhaitables pour un opérateur de réseau en ce qui concerne la manière dont il facture les consommateurs, certaines de nos solutions sont conçues pour satisfaire à ces principes. Ces principes sont : l'indépendance aux demandes supérieure et la péréquation. Enfin, certaines solutions parviennent aussi à prendre en compte les différentes informations fournies par le réseau de distribution.Cette thèse est constituée de sept chapitres. Le Chapitre 1 fait office d'introduction. Le Chapitre 2 introduit les notations et les définitions nécessaires à la bonne compréhension de la thèse. Les Chapitres 3 à 6 contiennent les contributions de la thèse.Chacune de ces contributions apporte ses propres solutions.Nous caractérisation axiomatiquement chacune d'entre elles et discutons de leur pertinence dans le cadre de la distribution de gaz. Enfin, le Chapitre 7 conclut la thèse.