Publications
Historically and in many parts of the developing world, ethnic minorities have played a central role in the economy. Examples include Chinese throughout South-east Asia, Indians in East Africa, and Jews in medieval Europe. These rich minorities are often subject to popular violence and extortion, and are treated ambiguously by local politicians. We analyse the impact of the presence of a rich ethnic minority on violence and on interactions between a rent-seeking local elite and a poor majority. We find that the local elite can always make use of the rich minority to maintain its hold on power. When the threat of violence is high, the government may change its economic policies strategically to sacrifice the minority to popular resentment. We investigate the conditions under which such instrumental scapegoating emerges, and the forms it takes. We then introduce some social integration, capturing, for instance, mixed marriages and shared education. Social integration reduces violence and yields qualitative changes in economic policies. Overall, our results help to explain documented patterns of violence and segregation.
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.
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.
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.
Why do some societies have political institutions that support productively inefficient outcomes? And why does the political power of elites vested in these outcomes often grow over time, even when they are unable to block more efficient modes of production? We propose an explanation centered on the interplay between political and cultural change. We build a model in which cultural values are transmitted inter-generationally. The cultural composition of society, in turn, determines public-goods provision as well as the future political power of elites from different cultural groups. We characterize the equilibrium of the model and provide sufficient conditions for the emergence of cultural revivals. These are characterized as movements in which both the cultural composition of society as well as the political power of elites who are vested in productively inefficient outcomes grow over time. We reveal the usefulness of our framework by applying it to two case studies: the Jim Crow South and Turkey’s Gülen Movement.
