Publications
This paper is an introduction to the special issue of Mathematical Social Sciences on Advances in growth and macroeconomic dynamics in memory of Carine Nourry.
This paper is a tribute for Carine Nourry for this special issue of Mathematical Social Sciences.
The relationship between public debt, growth and volatility is investigated in a Barro-type (1990) endogenous growth model, with three main features: we consider a small open economy, international borrowing is constrained and households have taste for domestic public debt. Therefore, capital, public debt and the international asset are not perfect substitutes and the economy is characterized by an investment multiplier. Whatever the level of the debt-output ratio, the existing BGP features expectation-driven fluctuations. If the debt-output ratio is low enough, there is also a second BGP with a lower growth rate. Hence, a lower debt does not stabilize the economy with credit market imperfections. However, a high enough taste for domestic public debt may rule out the BGP with lower growth. This means that if the share of public debt held by domestic households is high enough, global indeterminacy does not occur.
We study approachability theory in the presence of constraints. Given a repeated game with vector payoffs, we study the pairs of sets (A,D) in the payoff space such that Player 1 can guarantee that the long-run average payoff converges to the set A, while the average payoff always remains in D. We provide a full characterization of these pairs when D is convex and open, and a sufficient condition when D is not convex.
Face à la crise de nos systèmes traditionnels et à la précarisation du marché du travail, il devient nécessaire de favoriser des modèles de travail plus durables. L’économie sociale et solidaire (ESS) a toujours été pionnière en la matière. Groupements d’employeurs, coopératives d’activités et d’emplois, Scop et Scic, Territoires zéro chômeur de longue durée, tiers-lieux… L’ESS expérimente, innove, invente des modèles de travail et d’emploi plus protecteurs pour les travailleurs, plus ancrés dans les territoires, plus respectueux de l’humain. À ce titre, elle peut impulser une dynamique de changement inspirante pour l’ensemble de la société.
Comment ces initiatives positives d’ESS peuvent-elles essaimer pour permettre le développement d’un grand nombre d’emplois de qualité dans ou hors salariat : des emplois à la fois porteurs de sens, sécurisés et inscrits dans un collectif de travail, à rebours de la tendance actuelle à l’ubérisation ? Et comment imaginer un modèle de management qui favorise cette organisation épanouissante, loin des systèmes fondés sur la surveillance des salariés et la verticalité ? L’auteur avance des pistes à la fois souhaitables et réalistes, en faveur d’une meilleure cohésion de la société, d’une solidarité accrue et du renforcement des liens sociaux.
This paper examines how the degree of gender-egalitarianism embedded in inheritance rules impacts state capacity at its early stages during medieval times. We present a theoretical model in which building state capacity enables nobles to raise taxes and overcome rivals. The model addresses the use of inheritance to consolidate landholding dynasties, also accommodating interstate marriages between landed heirs. On the one hand, dynastic continuity—of utmost importance to medieval lords—directly encourages state-building. Male-biased inheritance rules historically maximize the likelihood of dynastic continuity. We weigh this effect against the indirect impact of the more frequent land-merging marriages under gender-egalitarian rules. Contrary to the literature, our results suggest that gender-egalitarian norms—offering a low probability of dynastic continuity—promote state capacity in the short run more than gender-biased norms. In the long run, results are reversed, providing a rationale for the pervasive European tradition of preference for men as heirs.
This paper estimates trade barriers in government procurement, a market that accounts for 12% 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 been shrinking 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 containing transparency and procedural requirements drive the liberalizing effect of trade agreements.
Petty corruption is a barrier to entrepreneurship in emerging countries, justifying to investigate its determinants. Using data on 1,240 entrepreneurs across Indonesian regions, we analyse the effects of social capital. Two-evel ordered probit regressions show that weak-ties discourage entrepreneurs' bribing, strong-ties encourage it, whereas this latter effect is moderated by the quality of access to formal credit. Bribing banks or turning to relatives for external funding are alternative solutions for entrepreneurs facing poor access to formal credit, a common feature in emerging countries, and the second solution is preferred given the risk and psychological costs of corruption.
The paper models evolution in pecunia—in the realm of finance. Financial markets are explored as evolving biological systems. Diverse investment strategies compete for the market capital invested in long-lived dividend-paying assets. Some strategies survive and some become extinct. The basis of our paper is that dividends are not exogenous but increase with the wealth invested in an asset, as is the case in a production economy. This might create a positive feedback loop in which more investment in some asset leads to higher dividends which in turn lead to higher investments. Nevertheless, we are able to identify a unique evolutionary stable investment strategy. The problem is studied in a framework combining stochastic dynamics and evolutionary game theory. The model proposed employs only objectively observable market data, in contrast with traditional settings relying upon unobservable investors’ characteristics (utilities and beliefs). Our method is analytical and based on mathematical reasoning. A numerical illustration of the main result is provided.
We provide the first analysis of the risk-sharing implications of altruism networks. Agents are embedded in a fixed network and care about each other. We explore whether altruistic transfers help smooth consumption and how this depends on the shape of the network. We find that altruism networks have a first-order impact on risk. Altruistic transfers generate efficient insurance when the network of perfect altruistic ties is strongly connected. We uncover two specific empirical implications of altruism networks. First, bridges can generate good overall risk sharing, and, more generally, the quality of informal insurance depends on the average path length of the network. Second, large shocks are well-insured by connected altruism networks. By contrast, large shocks tend to be badly insured in models of informal insurance with frictions. We characterize what happens for shocks that leave the structure of giving relationships unchanged. We further explore the relationship between consumption variance and centrality, correlation in consumption streams across agents, and the impact of adding links.
