Geographic Spillover of Unionism

According to the author, unionism in the United States is contagious; it spills out of coal mines and steel mills into other establishments in the neighborhood, like hospitals and supermarkets. The geographic spillover of unionism is documented here using a newly constructed establishment level data on unionism that is rich in geographic detail. A strong connection is found between unionism of health care establishments today and proximity to unionized coal mines and steel mills from the 1950s.