Exit, Assimilation, and Mobilization after Conquest: Evidence from Alsace-Lorraine

Research on conquest finds seemingly divergent legacies across cases: some societies accommodate and assimilate, while others resist with anti-conqueror backlash and emigration. I argue that these patterns are not competing case-level outcomes, but different aggregations of individuals pursuing mutually exclusive strategies. I study how intellectuals in Alsace-Lorraine responded to the German conquest of 1870 and the French reconquest of 1918, leveraging a difference-in-differences design and novel cross-border data on historical book publications. Both conquests triggered large shifts toward the conqueror's language as well as selective emigration. Among those who remained, within-individual estimates reveal a clear trade-off: assimilation and regionalist mobilization are substitute strategies. A new decomposition separates behavioral change from compositional change, and provides a sensitivity analysis for treatment effects under selection. Conquest therefore produces not uniform cultural change but strategic sorting, a finding that reconciles contradictory empirical patterns in the study of border change, violence, and nation-building.