Publications

Résumé We identify two counteracting effects of credit access on productivity growth: on the one hand, better access to credit makes it easier for entrepreneurs to innovate; on the other hand, better credit access allows less efficient incumbent firms to remain longer on the market, thereby discouraging entry of new and potentially more efficient innovators. We first develop a simple model of firm dynamics and innovation‐based growth with credit constraints, where the above two counteracting effects generate an inverted‐U relationship between credit access and productivity growth. Then we test our theory on a comprehensive French manufacturing firm‐level dataset. We first show evidence of an inverted‐U relationship between credit constraints and productivity growth when we aggregate our data at the sectoral level. We then move to firm‐level analysis, and show that incumbent firms with easier access to credit experience higher productivity growth, but that they also experience lower exit rates, particularly the least productive firms among them. To support these findings, we exploit the 2012 Eurosystem's Additional Credit Claims programme as a quasi‐experiment that generated an exogenous extra supply of credits for a subset of incumbent firms.
Mots clés Credit constraint, Firms, Growth, Interest rate, Productivity
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Résumé The Great Recessions was essentially a 'mancession' in countries like Spain, the UK or the US, i.e. it hit men harder than women for they were disproportionately represented in heavily affected sectors. We investigate how the mancession, and more generally women's relative opportunities on the labor market, translate into within-household redistribution. Precisely, we estimate the spouses' resource shares in a collective model of consumption, using Spanish data over 2006-2011. We exploit the gender-oriented evolution of the economic environment to test two original distribution factors: first the regional-time variation in spouses' relative unemployment risks, then the gender-differentiated shock in the construction sector (having a construction sector husband after the outburst of the crisis). Both approaches conclude that the resource share accruing to Spanish wives increased by around 7-9 percent on average, following the improvement of their relative labor market positions. Among childless couples, we document a 5-11 percent decline in individual consumption inequality following the crisis, which is essentially due to intrahousehold redistribution.
Mots clés Mancession, Intrahousehold allocation, Unemployment, Gender, Great recession, Spain, Inequality, Inégalité, Espagne, Grande récession, Genre, Allocation intra-ménage, Allocation intra-familiale
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Résumé We review the most recent advances in distributed optimal control applied to Environmental Economics, covering in particular problems where the state dynamics are governed by partial differential equations (PDEs). This is a quite fresh application area of distributed optimal control, which has already suggested several new mathematical research lines due to the specificities of the Environmental Economics problems involved. We enhance the latter through a survey of the variety of themes and associated mathematical structures beared by this literature. We also provide a quick tour of the existing tools in the theory of distributed optimal control that have been applied so far in Environmental Economics.
Mots clés Environmental economics, Distributed systems, Optimal control, Partial differential equations
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Résumé This paper explores the relationship between past climate and prehistoric Mediterranean agriculture by adapting a process-based dynamic vegetation model to estimate potential agricultural productivity under climate scenarios that characterize the extremes of Mediterranean climate in the Holocene. We adapt LPJmL (the Lund-Potsdam-Jena-managed-land model [Bondeau et al., 2007]), a process-based dynamic vegetation model, to the modeling of potential agricultural productivity in the past. Calibrating this model for past crops and agricultural practices and using a downscaling approach to produce high spatiotemporal resolution paleoclimate data, we produce quantitative estimates of potential yields under past climatic conditions derived from four Holocene climatic extremes (warm/wet, warm/dry, cold/wet, and cold/dry) under two different assumptions (approximate high and low limits) about the intensity of agricultural practice. We here discuss this process with reference to a case study in Provence, examining the methodology and data requirements for modeling past agriculture using LPJmL and considering the implications of the range of variability in potential agricultural productivity under distinct climate conditions. We focus particularly on comparing the range of variability induced by climatic shifts with that achievable through changes in agricultural practices as a means of approaching questions of past vulnerability and resilience.
Mots clés Prehistoric agriculture, Human-environment interaction, Agro-ecosystem modeling, Past climate impacts
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Résumé The promotion system for French academic economists provides an interesting environment to examine the promotion gap between men and women. Promotions occur through national competitions for which we have information both on candidates and on those eligible to be candidates. Thus, we can examine the two stages of the process: application and success. Women are less likely to seek promotion, and this accounts for up to 76 percent of the promotion gap. Being a woman also reduces the probability of promotion conditional on applying, although the gender difference is not statistically significant. Our results highlight the importance of the decision to apply.
Mots clés Gender gaps, Professional advancement, Competition
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Résumé We solve a linear-quadratic model of a spatio-temporal economy using a polluting one-input technology. Space is continuous and heterogenous: locations differ in productivity, nature self-cleaning technology and environmental awareness. The unique link between locations is transboundary pollution which is modelled as a PDE diffusion equation. The spatio-temporal functional is quadratic in local consumption and linear in pollution. Using a dynamic programming method adapted to our infinite dimensional setting, we solve the associated optimal control problem in closed-form and identify the asymptotic (optimal) spatial distribution of pollution. We show that optimal emissions will decrease at given location if and only if local productivity is larger than a threshold which depends both on the local pollution absorption capacity and environmental awareness. Furthermore, we numerically explore the relationship between the spatial optimal distributions of production and (asymptotic) pollution in order to uncover possible (geographic) environmental Kuznets curve cases.
Mots clés Transboundary pollution, Infinite dimensional optimal control problems, Geography, Growth
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Résumé What would be the analogue of the Lorenz quasi-ordering when the variable of interest is continuous and of a purely ordinal nature? We argue that it is possible to derive such a criterion by substituting for the Pigou-Dalton transfer used in the standard inequality literature what we refer to as a Hammond progressive transfer. According to this criterion, one distribution of utilities is considered to be less unequal than another if it is judged better by both the lexicographic extensions of the maximin and the minimax, henceforth referred to as the leximin and the antileximax, respectively. If one imposes in addition that an increase in someone’s utility makes the society better off, then one is left with the leximin, while the requirement that society welfare increases as the result of a decrease of one person’s utility gives the antileximax criterion. Incidentally, the paper provides an alternative and simple characterisation of the leximin principle widely used in the social choice and welfare literature.
Mots clés Leximin, Antileximax, Ordinal inequality, Hammond equity principle, Inégalité ordinale, Equité au sens de Hammond, Leximin, Antileximax
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Résumé This article shows how the increase of information availability due to new technologies positively affects aggregate entrepreneurship in national economies. We rely on an “occupational choice” model of managerial production, extended to include the managerial use of information, to explain variations in the number of entrepreneurs, and thus of firms, as measured by the aggregate new business creation data. We present evidence that supports such a theory of industrial organization dynamics for a sample of 78 economies over the period 2004–2012 using panel data instrumental variable regressions.
Mots clés Industrial organization, Managerial information, Information and communication technologies, Entrepreneurship
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Résumé Cet article présente une description multidimensionnelle de la pauvreté des enfants en France, au moment de leur naissance et au cours de leur première année de vie. Plus précisément, il s’appuie sur deux principales mesures de pauvreté : la pauvreté monétaire et la pauvreté en conditions de vie (et de logement). L’approche généralement utilisée pour mesurer la pauvreté des adultes est ainsi appliquée aux jeunes enfants, ce qui permet de prendre en compte leurs besoins spécifiques. Diverses techniques de régression ont été mobilisées afin de mettre en évidence les groupes de population les plus vulnérables à la pauvreté monétaire et à la pauvreté en conditions de vie dans ses différentes dimensions.
Mots clés Enfants, Pauvreté, Conditions de vie, Enquête Elfe, France
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Résumé This paper develops a simple business-cycle model in which financial shocks have large macroeconomic effects when private agents are gradually learning the uncertain environment. Agents update their beliefs about the reduced-form structure of the economy. Because the persistence of leverage is overestimated by adaptive learners, the responses of output, investment, and other aggregates under adaptive learning are significantly larger than under rational expectations. In our benchmark case calibrated using US data on leverage, debt-to-GDP and land value-to-GDP ratios for 1996Q1–2008Q4, learning amplifies leverage shocks by a factor of about three, relative to rational expectations. When fed with actual leverage innovations observed over that period, the learning model predicts that the persistence of leverage shocks is increasingly overestimated after 2002 and that a sizeable recession occurs in 2008–2010, while its rational expectations counterpart predicts a counter-factual expansion. In addition, we show that procyclical leverage reinforces the amplification due to learning and, accordingly, that macro-prudential policies that enforce countercyclical leverage dampen the effects of leverage shocks.
Mots clés Adaptive learning, Collateral constraints, Financial shocks, Great recession
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