About me

I am Carl Gaigné, Born November 1, 1972, and a senior scientist (Directeur de recherches INRAE, 1ere classe). I am an economist specialized in location of people and jobs as well as in international trade (their determinants and their economic, environmental and social implications). I conduct research that stresses the importance of considering long-run and distributional effects when evaluating the impact of public policies. In most literature, the analysis of the efficiency of policies disregards the long-run adjustments induced by the public regulations. In a series of articles published in top journals, I found that the short-run positive effects of a policy can be weakened by long-run negative effects or can be lower than long-run negative effects when the location of production factors and the entry/exit of producers adjusts to this policy. In addition, my research shows that public regulations, including non-discriminatory policies, may yield large reallocations of resources in the long run across agents and across locations, which create winners and losers. My research points out the need to take transition cost mitigation strategies seriously, and incorporate them systematically in policies to be implemented.

I make contributions by developing new theories of trade and location that models both short-run decisions by a myriad of heterogeneous agents and long-run choices involving scale economies. I hope that my (recent) models are rich enough to speak to first-order features of the data (like the role of market structure, technology, and geography), yet parsimonious enough so that one can identify its key parameters and implement in a transparent way an evaluation of policies. My analysis has shed light on the design of trade, environmental, and urban policies. When public policies affect prices, transaction costs, and standards, it is reasonable to expect the entry or exit of producers and locations changes in the long run, what, in turn, modifies economic, ecological, and social outcomes. Accounting for these general equilibrium effects makes the long-term impacts of public regulations complex, the reason being that the new distribution of resources need not be better from the efficiency and equity viewpoints. I have shown that (i) it can be very costly to ignore these long-run effects when determining public regulations and (ii) there is not always a trade-off between efficiency and equity, contrary to the widespread belief.

The orientations of my research are motivated by empirical observations that are not well explained in the academic literature. I am also attentive to issues that emerge from public debates. I try to build rigorous theoretical frameworks to rationalize the observed facts. I am also willing to empirically test theories and to conduct counterfactual analyses (what would happen if...). I also try to set up methodologies to evaluate ex ante or ex post the effects of public policies. My scientific concerns have obviously evolved over time due to the evolution of the economic context and my skills, but also to my readings and meetings. Since the beginning of my career, I also frequently carry out expertise and transfer activities with non-academic audiences (public decision-makers, professionals, students, ...) or with scientific audiences outside the social sciences.