Publications
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.
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.
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We adopt a philosophical perspective of equality of opportunity and address the issue of whether outcome inequalities are legitimate when they come from differences in talent. We propose a cumulative definition of talent. In a dynamic setting, talent is a by-product of past-effort, current effort and innate talent, which becomes a residual as time goes by. It implies that talent can change from the status of a circumstance when people are young to an almost responsibility variable when people are getting older. We plug this definition of talent into the Mirrlees model of optimal non-linear income tax and we show that the conflict between the principle of compensation and the principle of natural reward boils down to the optimal income tax with Rawlsian weights in the second-best setting.
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.
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.
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.
We consider the link between birthplace and wages. Using a unique panel dataset, we estimate a raw elasticity of wages with respect to birthplace size of 4.2%, two thirds of the 6.8% raw elasticity with respect to city size. Part of this effect simply reflects intergenerational transmission and the spatial sorting of parents, part is explained by the role that birthplace size plays in determining current city size. Lifetime immobility explains a lot of the correlation between birthplace and current city size: we show that 43.7% of individuals only ever work while living in the place they were born. Our results highlight the importance of intergenerational and individual sorting in helping explain the persistence of spatial disparities.
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.





