Publications

Abstract Attitude théorique et pratique, la philosophie économique est une démarche intellectuelle qui articule économie et philosophie. Mais comment la définir ? Et d’où vient l’intérêt grandissant que l’on constate depuis vingt ans ? Quelles ressources pluralistes mobilise-t-elle et comment s’est-elle constituée ? Quels rapports entretient-elle avec la théorie économique, l’histoire de la pensée et les philosophies morale et politique ? À ces questions, notamment, et en s’appuyant sur l’ouvrage collectif Philosophie économique. Cette introduction donne des réponses fondamentales, claires et précises.
Keywords Philosophie économique, Economie politique
HAL Google Scholar
Abstract In this paper we investigate if government balanced-budget rules together with endogenous taxation may lead to aggregate instability in an endogenous growth framework. After highlighting the differences with the exogenous growth framework, we prove that under counter-cyclical consumption taxes, while there exists a unique balanced growth path, sunspot equilibria based on self-fulfilling expectations occur through a form of global indeterminacy. In addition, we argue that this result is empirically plausible for a large set of OECD countries and that it may also emerge with endogenous income taxes.
Keywords Sunspot equilibria, Self‐fulfilling expectation, Global indeterminacy, Time‐varying consumption tax, Endogenous growth
Publication HAL Google Scholar
Abstract We consider different approaches for assessing variable importance in clustering. We focus on clustering using binary decision trees (CUBT), which is a non-parametric top-down hierarchical clustering method designed for both continuous and nominal data. We suggest a measure of variable importance for this method similar to the one used in Breiman’s classification and regression trees. This score is useful to rank the variables in a dataset, to determine which variables are the most important or to detect the irrelevant ones. We analyze both stability and efficiency of this score on different data simulation models in the presence of noise, and compare it to other classical variable importance measures. Our experiments show that variable importance based on CUBT is much more efficient than other approaches in a large variety of situations.
Keywords Variable importance, Deviance, CUBT, Unsupervised learning, Variables ranking
Publication HAL Google Scholar
Abstract This paper provides direct evidence that learning about demand is an important driver of firms’ dynamics. We present a model of Bayesian learning in which firms are uncertain about idiosyncratic demand in each market and update their beliefs as noisy information arrives. Firms update their beliefs to a given demand shock more, the younger they are. We test and empirically confirm this prediction, using the structure of the model, together with exporter-level data, to identify demand shocks and the firms’ beliefs about future demand. Consistent with theory, we also find the learning process to be weakened in more uncertain environments.
Keywords Exports, Demand, Firm growth, Belief updating, Uncertainty
Publication HAL Google Scholar
Abstract We estimate the effect of the share of ethnic groups included in the central government on economic growth, distinguishing between democracies and autocracies in a panel of 41 Sub-Saharan African countries over the period from independence to 1999. We exploit evidence from the Ethnic Power Relations database, which categorises the politically relevant ethnic groups regarding access to state power. We take advantage of the time variation of political participation, using Fixed-Effects and Difference-GMM estimations. Our dynamic-panel growth models display a robust positive effect of the proportion of included groups in democracies. Such an effect is offset in autocracies, and the difference is often significant. This finding withstands the introduction of various controls, outlier tests, and specification checks. Our results support the view that institutional improvements must accompany the promotion of inclusiveness in low-income and weakly-institutionalised countries.
Keywords Institutions, Ethnic coalitions, Growth regressions
Publication HAL Google Scholar
Abstract A pure Hotelling game is a spatial competition between a finite number of players who simultaneously select a location in order to attract as many consumers as possible. In this paper, we study the case of a general distribution of consumers on a network generated by a metric graph. Because players do not compete on price, the continuum of consumers shop at the closest player’s location. If the number of sellers is large enough, we prove the existence of an approximate equilibrium in pure strategies, and we construct it.
Keywords Large games, Approximate Nash equilibria, Pure equilibria, Location games on networks, Hotelling games
Publication HAL Google Scholar
Abstract The interplay between growth and public debt is addressed considering a Barro-type (1990) endogenous growth model where public spendings are financed through taxes on income and public debt. The government has a target level of public debt relative to GDP, and the long-run debt-to-GDP ratio is used as a policy parameter. We show that when debt is a large enough proportion of GDP, two distinct balanced-growth paths (BGPs) may coexist, one being indeterminate. We exhibit two types of important trade-offs associated with self-fulfilling expectations. First, we show that the lowest BGP is always decreasing with respect to the debt-to-GDP ratio while the highest one is increasing. Second, we show that the highest BGP, which provides the highest welfare, is always locally indeterminate while the lowest is always locally determinate. Therefore, local and global indeterminacy may arise and self-fulfilling expectations appear as a crucial ingredient to understand the impact of debt on growth, welfare, and macroeconomic fluctuations. Finally, a simple calibration exercise allows to provide an understanding of the recent experiences of many OECD countries.
Publication HAL Google Scholar
Abstract This paper stresses a new channel through which global financial linkages contribute to the co‐movement in economic activity across countries. We show in a two‐country setting with borrowing constraints that international credit markets are subject to self‐fulfilling variations in the world real interest rate. Those expectation‐driven changes in the borrowing cost in turn act as global shocks that induce strong cross‐country co‐movements in both financial and real variables (such as asset prices, gross domestic product, consumption, investment, and employment). When firms around the world benefit from unexpectedly low debt repayments, they borrow and invest more, which leads to excessive supply of collateral and of loanable funds at a low interest rate, thus fueling a boom both at home and abroad. As a consequence, business cycles are synchronized internationally. Such a stylized model thus offers one way to rationalize both the existence of a world business‐cycle component, documented by recent empirical studies through dynamic factor analysis, and the factor's intimate link to global financial markets.
Keywords World interest rate, International co-movement, Self-fulfilling equilibria
Publication HAL Google Scholar
Abstract Why do some OECD countries have high levels of procedural formalism (PF) in the housing market? We provide an explanation based upon complementarities between the strength of social networks and the stringency of procedural formalism. The interest of social networks is that conflict resolution is independent from the law. When local agents belong to social networks whereas non-local agents do not, PF may facilitate housing search for locals at the expense of non-locals. To illustrate this mechanism we build a search-theoretic model of the housing market. The model emphasizes that the demand for PF occurs when the size of social networks is large. By simulations, we show that the support for PF increases with the size of social networks, the default probability on the rent and the proportion of non-local agents.
Publication HAL Google Scholar