Migration and innovation : the impact of East German inventors on West Germany's technological development

We investigate the causal relationship between inventor migration and regional innovation in the context of the large-scale migration shock from East to West Germany between World War II and the construction of the Berlin Wall in 1961. Leveraging a newly constructed, century-spanning dataset on German patents and inventors, along with an innovative identification strategy based on surname proximity, we trace the trajectories of East German inventors and quantify their impact on innovation in West Germany. Our findings demonstrate a significant and persistent boost to patenting activities in regions with higher inflows of East German inventors, predominantly driven by advancements in chemistry and physics. We further validate the robustness of our identification strategy against alternative plausible mechanisms. We show in particular that the effect is stronger than the one caused by the migration of other high skilled workers and scientists.