Trade Shocks, Institutions, and Political Polarization: Evidence from France

Across Europe, center-left parties are in serious trouble, severely weakened by challenges from increasingly successful far-left and far-right parties.  What are the drivers of this increasing political polarization?  While much scholarly attention has been devoted to the sources of support for radical right parties, we know far less about the causes of broader patterns of polarization in Western Europe. 

This paper draws on data from France, in which polarization has grown substantially over the past thirty years, to explore both demand- and supply-side explanations for political polarization.  We analyze patterns of polarization among two populations: voters and political elites.  The paper is organized into two parts.  As a first step, we draw upon administrative data and an instrumental variables strategy to investigate the relationship between trade-exposure in local labor markets and political polarization.  Here, we explore the extent to which import shocks drive support for radical parties, and whether this is driven by an anti-incumbent or a re-alignment dynamic.  Second, using original data on voting in the French Senate, we leverage a discontinuity in assignment to different types of electoral rules to examine the extent to which the degree of polarization among political elites is affected by the nature of electoral institutions.