Séminaires LEMMA

"The Gravity of Violence"

Thierry Mayer (Sciences Po), Co-authors: Mathieu Couttenier, Julian Marcoux, and Mathias Thoenig

Thierry is Professor of Economics at Sciences Po and Elected Fellow of the Econometric Society. His research interest lies in international trade, multinational firms, economic geography, location theory, and industrial organization.

Monday, 31 March 2026, 11h-12h

Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas

Abstract : This paper presents a framework for estimating and simulating a quantitative spatial model of trade and violent conflict. In this new theoretical and empirical setup, designed for the analysis of bilateral flows, we first model the general equilibrium interactions between the economic and fighting margins in a micro-founded setup. We then show how the structural parameters can be recovered from the data in a simple and transparent way. A central element of the procedure consists in estimating a structural gravity equation of violence. Studying continental Africa over the period 1997 to 2023, we test the key predictions of the model and uncover new facts related to spatial frictions and conflicts. Finally, the model is simulated to quantify different policy-relevant experiments in weakly institutionalized contexts where insecurity is pervasive. Positive and spatially-diffusing feedback loops between development and pacification are one of the main findings of our analysis. 

"Extreme Points in Multi-Dimensional Screening"

Patrick Lahr (ENS Paris-Saclay)

Patrick est un théoricien de la microéconomie spécialisé en mechanism design. 

Monday, 24 March 2026, 11h-12h

Lemma - 4 rue Blaise Desgoffe, 75006 Paris. Salle Maurice Desplas