Publications

Résumé This study aims to evaluate people’s willingness to provide their geospatial global positioning system (GPS) data from their smartphones during the COVID-19 pandemic. Based on the self-determination theory, the addition of monetary incentives to encourage data provision may have an adverse effect on spontaneous donation. Therefore, we tested if a crowding-out effect exists between financial and altruistic motivations. Participants were randomized to different frames of motivational messages regarding the provision of their GPS data based on (1) self-interest, (2) pro-social benefit, and (3) monetary compensation. We also sought to examine the use of a negative versus positive valence in the framing of the different armed messages. 1055 participants were recruited from 41 countries with a mean age of 34 years on Amazon Mechanical Turk (MTurk), an online crowdsourcing platform. Participants living in India or in Brazil were more willing to provide their GPS data compared to those living in the United States. No significant differences were seen between positive and negative valence framing messages. Monetary incentives of $5 significantly increased participants’ willingness to provide GPS data. Half of the participants in the self-interest and pro-social arms agreed to provide their GPS data and almost two-thirds of participants were willing to provide their data in exchange for $5. If participants refused the first framing proposal, they were followed up with a “Vickrey auction” (a sealed-bid second-priced auction, SPSBA). An average of $17 bid was accepted in the self-interest condition to provide their GPS data, and the average “bid” of $21 was for the pro-social benefit experimental condition. These results revealed that a crowding-out effect between intrinsic and extrinsic motivations did not take place in our sample of internet users. Framing and incentivization can be used in combination to influence the acquisition of private GPS smartphone data. Financial incentives can increase data provision to a greater degree with no losses on these intrinsic motivations, to fight the COVID-19 pandemic.
Mots clés Economics, Science, Technology and society, Sociology
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Résumé This paper examines the effect of weather shocks on violent crime using disaggregated data from Brazilian municipalities over the period 1991–2015. Employing a distributed lag model that takes into account temporal correlations of weather shocks and spatial correlation of crime rates, I document that adverse weather shocks in the form of droughts lead to a significant increase in violent crime in rural regions. This effect appears to persist beyond the growing season and over the medium run in contrast to the conventional view perceiving weather effects as transitory. To explain this persistence, I show that weather fluctuations are positively associated not only with agriculture yields, but also with the overall economic activity. Moreover, evidence shows the dominance of opportunity cost mechanism reflected in the fluctuations of the earnings especially for the agriculture and unskilled workers, giving credence that it is indeed the income that matters and not the general socio-economic conditions. Other factors such as local government budget capacity, (un)-employment, poverty, inequality, and psychological factors do not seem to explain violent crime rates.
Mots clés Weather shocks, Violent crime, Labor Market, Brazil
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Résumé Although the Covid-19 crisis has shown how high-frequency data can help track the economy in real time, we investigate whether it can improve the nowcasting accuracy of world GDP growth. To this end, we build a large dataset of 718 monthly and 255 weekly series. Our approach builds on a Factor-Augmented MIxed DAta Sampling (FA-MIDAS), which we extend with a preselection of variables. We find that this preselection markedly enhances performances. This approach also outperforms a LASSO-MIDAS—another technique for dimension reduction in a mixed-frequency setting. Though we find that a FA-MIDAS with weekly data outperform other models relying on monthly or quarterly data, we also point to asymmetries. Models with weekly data have indeed performances similar to other models during “normal” times but can strongly outperform them during “crisis” episodes, above all the Covid-19 period. Finally, we build a nowcasting model for world GDP annual growth incorporating weekly data that give timely (one per week) and accurate forecasts (close to IMF and OECD projections but with 1- to 3-month lead). Policy-wise, this can provide an alternative benchmark for world GDP growth during crisis episodes when sudden swings in the economy make usual benchmark projections (IMF's or OECD's) quickly outdated.
Mots clés Variable selection, Nowcasting, Mixed frequency, Large factor models, High frequency, Big data
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Résumé In this paper we introduce a definition of approximate Pareto efficient solution as well as a necessary condition for such solutions in the multiobjective setting on Riemannian manifolds. We also propose an inexact proximal point method for nonsmooth multiobjective optimization in the Riemannian context by using the notion of approximate solution. The main convergence result ensures that each cluster point (if any) of any sequence generated by the method is a Pareto critical point. Furthermore, when the problem is convex on a Hadamard manifold, full convergence of the method for a weak Pareto efficient solution is obtained. As an application, we show how a Pareto critical point can be reached as a limit of traps in the context of the variational rationality approach of stay and change human dynamics.
Mots clés Multiobjective proximal method, Riemannian manifold, Approximate solution, Variational rationality, Worthwhile moveTrap
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Résumé The interest rate at which US firms borrow funds has two features: (i) it moves in a countercyclical fashion and (ii) it is an inverted leading indicator of real economic activity: low interest rates today forecast future booms in GDP, consumption, investment, and employment. We show that a Kiyotaki–Moore model accounts for both properties when interest-rate movements are driven, in a significant way, by self-fulfilling belief shocks that redistribute income away from lenders and to borrowers during booms. The credit-based nature of such self-fulfilling equilibria is shown to be essential: the dynamic correlation between current loanable funds rate and future aggregate economic activity depends critically on the property that the interest rate is state-contingent. Bayesian estimation of our benchmark DSGE model on US data shows that the model driven by redistribution shocks results in a better fit to the data than both standard RBC models and Kiyotaki–Moore type models with unique equilibrium.
Mots clés Multiple equilibria, Redistribution shocks, State-contingent interest rate, Endogenous collateral constraints
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Résumé This paper estimates trade barriers in government procurement, a market that accounts for 12 percent of world GDP. Using data from inter-country input-output tables in a gravity model, we find that home bias in government procurement is significantly higher than in trade between firms. However, this difference has decreased over time. Results also show that trade agreements with provisions on government procurement increase cross-border flows of services, whereas the effect on goods is small and not different from that in private markets. Provisions on transparency and procedural requirements are particularly instrumental in increasing cross-border government procurement.
Mots clés Government procurement, Trade agreements, Gravity equation
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Résumé This paper examines the adaptation policy of Small Island Developing States (SIDS) facing climate change. We consider a dynamic economy with the following ingredients: (i) natural capital is an input in local production that is degraded as a result of climate change; (ii) the government has two instruments to cope with climate-related damages: it can adjust the population size thanks to migration policies and/or it can undertake adaptation measures in order to slow the degradation of natural assets; (iii) expatriates send remittances back home. We identify two critical conditions on the fundamentals of the economy that helps understand the features of the optimal policy. We especially show that in most situations, the migration policy is a valuable instrument. Calibrating the model for Caribbean SIDS, we find that the optimal policy of the Caribbean region displays heterogeneity, that is explained by the different degradation rate, population size, and endowment in natural capital. We also highlight that the higher the climate damages, the higher the incentives to conduct an active adaptation policy, combining conventional adaptation actions and migration..
Mots clés SIDS, Climate change, Adaptation, Migration, Natural capital, Optimal policy-mix
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Résumé 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.
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Résumé This paper addresses the question of the effectiveness and permanence of temporary incentives to contribute to a public good. Using a common experimental framework, we investigate the effects of a recommendation that takes the form of an exhortative message to contribute, a monetary punishment and a non-monetary reward to sustain high levels of contributions. In particular, we shed light on the differential impact these mechanisms have on heterogeneous types of agents. The results show that all three incentives increase contributions compared to a pre-phase where there is no incentive. Monetary sanctions lead to the highest contributions, but a sudden drop in contributions is observed once the incentive to punish is removed. On the contrary, Recommendation leads to the lowest contributions but maintains a long-lasting impact in the Postpolicy phase. In particular, it makes free-riders increase their contribution over time in the post-incentive phase. Finally, non-monetary reward backfires against those who are weakly conditional cooperators. Our findings emphasize the importance of designing and maintaining incentives not only for free-riders, but for strong and weak conditional cooperators as well, depending on characteristics of the incentives.
Mots clés Monetary policy, Game Theory, Conservation science, Experimental design, Experimental economics, Social psychology, Test statistics, Public goods game, Monetary policy
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Résumé This paper provides a long-run cycle perspective to explain the behavior of the annual flow of inheritance. Based on the low- and medium frequency properties of long time bequests series in Sweden, France, UK, and Germany, we explore the extent to which a two-sector Barro-type OLG model is consistent with such empirical regularities. As long as agents are sufficiently impatient and preferences are non-separable, we show that endogenous fluctuations are likely to occur through two mechanisms, which can generate independently or together either period-2 cycles or Hopf bifurcations. The first mechanism relies on the elasticity of intertemporal substitution or equivalently the sign of the cross-derivative of the utility function whereas the second rests on sectoral technologies through the sign of the capital intensity difference across two sectors. Furthermore, building on the quasi-palindromic nature of the degree-4 characteristic equation, we derive some meaningful sufficient conditions associated to the occurrence of complex roots and a Hopf bifurcation in a two-sector OLG model.
Mots clés Two-sector overlapping generations model, Altruism, Bequest, Endogenous fluctuations, Quasi-palindromic polynomial, Periodic and quasi-periodic cycles
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Résumé From different perspectives regarding the History of Economic Thought, the contributions to this roundtable highlight different aspects and levels of the modernity of the founder of the Austrian School of Economics, and of his importance for the development of social theory and the discipline of scientific economics. This is complemented by discussions of ambiguities and multiple meanings of modernity.
Mots clés Austrian economics, Carl Menger, Modern economics, Modernity, Enlightenment, Complexity economics, Subjectivism, Value theory
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Résumé Combining seven years of household data from an original eld experiment in villages of Jharkand, East India, with meteorological data, this paper investigates how Indian Self-Help Groups (SHGs) enable households to withstand rainfall shocks. I show that SHGs operate remarkably well under large covariate shocks. While credit access dries up in control villages one year after a bad monsoon, reecting strong credit rationing from informal lenders, credit ows are counter-cyclical in treated villages. Treated households experience substantially higher food security during the lean season following a drought and increase their seasonal migration to mitigate expected income shocks. Credit access plays an important role, together with other SHG aspects such as peer networks. These ndings indicate that local self-help and nancial associations can help poor farmers to cope with climatic shocks and to implement risk management strategies.
Mots clés Seasonal migration, Food security, Resilience, Risk management, Climatic shocks, Credit, Micronance
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Résumé L'entreprise libérée est un concept qui fait beaucoup parler et écrire. D’aucuns la présentent comme une innovation managériale majeure et même un modèle organisationnel d’avenir. Pourtant, même si elle est une tentative de réponse intéressante aux problématiques de déplacement des valeurs et des attentes des collaborateurs au travail, elle semble plus être un habillage cosmétique qu’un véritable concept managérial. Il y a certainement mieux à faire en questionnant les postures attendues d’un manager aujourd’hui, plutôt qu’en promouvant l’apparent effacement du management. Nous proposons une révision conceptuelle à l’aide de l’éclairage postmoderne à travers la notion d’entreprise libérante. Nous suggérons ainsi, à travers ce travail théorique, une nouvelle piste en cherchant à repenser les grandes postures managériales. Nous proposons ainsi de cesser de vouloir libérer l’entreprise pour poser les bases de l’entreprise libérante. Ce travail de rénovation conceptuelle s’appuie sur une étude exploratoire qualitative menée auprès de managers « libérateurs ».
Mots clés Desires, Leadership, Postmodernity, Managerial Innovation, Free form Companies, Désirs, Leadership, Postmodernité, Innovation managériale, Entreprise libérée
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Résumé We study the canonical Krugman (1979) trade model with non-CES preferences that yield autarky at finite trade costs. We prove a non-monotone impact of gradual trade liberalization. At first, near autarky, emerging trade reduces world welfare, while at free trade it becomes large enough to be beneficial (Krugman's result). This non-monotonicity persists under heterogenous firms. The harmful small-scale trade is explained by variable markups and underpriced imports, which become socially excessive. Unlike protectionists, we argue that “liberalization should go far”. On the other hand, we show that anti-dumping measures can be viewed as a remedy for the aforementioned imports distortion.
Mots clés Autarky, Harmful trade, Variable markups, Monopolistic competition, Trade gains
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Résumé This paper presents an artefactual field experiment with craftsmen working on renovation projects to assess the effect of training programs and incentive schemes on coordination. Workers frequently fail to coordinate their tasks when not supervised by a project coordinator. This is particularly important in the construction sector where it leads to a lack of final performance in buildings. We introduce two different incentives: a first contract paying craftsmen only according to their individual performance, and a second contract paying a group of three craftsmen with a weak-link payment according to the group’s worst performance. In addition, we test these incentives on two different subject groups: one is composed of craftsmen trained to coordinate their tasks, and the others are not. The results suggest that trained subjects coordinate at significantly higher effort levels than non-trained subjects when facing an individual-based incentive. However, when facing a group-based incentive, non-trained subjects seem to ”catch up” trained subjects in terms of coordination level, while these latter subjects do not significantly increase their performance level.
Mots clés Coordination, Real-effort weak-link experiment, Artefactual field experiment, Individual incentive, Group incentive
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Résumé Souvent appréhendés à l’échelle internationale, ces acteurs sont ici étudiés dans leurs relations situées avec l’État, à partir d’une approche empirique et localisée. Parce qu’ils s’engagent dans les politiques de développement, ils deviennent des partenaires tolérés par le pouvoir selon différentes logiques de « décharge ». Tandis que leur périmètre d’action est soigneusement négocié avec les autorités publiques pour des raisons matérielles, statutaires et sécuritaires, la pérennité de leurs actions est due, entre autres, à leur capacité à négocier des combinaisons d’imaginaires politico-religieuses, ce qui ne les empêche pas de participer aux rapports de domination existants.
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Résumé We study, in a finite setting, the problem of Pareto rationalizability of choice functions by means of a preference profile that is single-peaked with respect to an exogenously given linear order over the alternatives. This problem requires a new condition to be added to those that characterize Pareto rationalizability in the general domain of orders (Moulin (1985)). This new condition appeals to the existence of a central range of options such that the choice function excludes alternatives which are distant from that range.
Mots clés Single-peaked preferences, Pareto rationalizability
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Résumé Canada exhibits no correlation between income and victimization, rich neighborhoods are less exposed to property crime, rich households are more victimized than their neighbors, and rich households and neighborhoods invest more in protection. We provide a theory consistent with these facts. Criminals within city choose a neighborhood and pay a search cost to compare potential victims, whereas households invest in self‐protection. As criminals' return to search increases with neighborhood income, households in rich neighborhoods are likelier to enter a race to greater protection driving crim-inals toward poorer areas. A calibration reproduces the Canadian victimiza-tion and protection pattern by household/neighborhood income.
Mots clés Search frictions, Property crime, Private protection, Economics of crime, Alarms
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