'Good' Firms, Worker Flows and Local Productivity

This paper is the first to present direct evidence showing how localized knowledge spillovers arise from workers changing jobs within the same local labor market. Using a unique data set combining Social Security earnings records and balance sheet information for the Veneto region of Italy, I first identify a set of highly productive firms, then show that hiring workers with experience at these firms significantly increases the productivity of other firms. My findings imply that worker flows explain around 10% of the productivity gains experienced by incumbent firms when new highly productive firms are added to a local labor market.