Human capital spillovers and the churning phenomenon: Analysing wage effects from gross in- and outflows of high-skilled workers

Abstract

The article estimates human capital externalities on wages originating from internal gross migration flows of high-skilled workers. We draw on rich administrative micro panel data that allow us to disentangle externalities from sorting and labour market supply and demand effects through an extensive set of time-varying fixed effects. We show that regional inflows and outflows of high-skilled workers occur simultaneously and that both are positively correlated. Given the existence of such a churning phenomenon, looking only at net migration flows might be misleading. Our econometric analysis indicates that inflows of high-skilled workers increase the wages of locals, whereas outflows decrease those wages. Although externalities from outflows outweigh those from inflows in the short run, the opposite holds in the long run. Our results suggest that human capital externalities are transmitted through the productivity effects of local personal networks, which, for newcomers, develop over time.