CREDIT Seminar: Pauline Grosjean (UNSW)

This is an online seminar

Title:  War, polarization, and partisanship (with Jha, Vlassopoulos and Zenou)

Abstract:  This study shows how political segregation and polarization can shift political tensions to new fault-lines, where they can degenerate into civil war. We develop a network model of polarization and partisanship that illustrates how, in the presence of multiple partisanship coordination equilibria (e.g. Left, Right), separate networks coordinate on different partisan equilibria so that the effect on overall polarization is ambiguous. We study this dynamic process of polarization empirically, exploiting the large-scale exogenous assignment of individuals to regiments in the context of World War I in France and highly granular panel voting data at the level of 36,000 municipalities. Fighting together in WWI decreases local polarization but does not, per se, explain partisan conversion. Instead, partisan shift to the left is explained by accidental exposure to socialist regiments, which we identify by exploiting local discontinuities in regimental assignment across 435 military boundaries. Partisan shift created sharp local polarization across military boundaries, where we observe more in-fighting between the Resistance and the Collaboration thirty years later, during WII.