Who do Unions Target? Unionization over the Life-Cycle of U.S. Businesses

What type of businesses do unions target for organizing and when? A dynamic model of the union organizing process is constructed to answer this question. A union monitors establishments in an industry to learn about their productivity, and decides which ones to organize and when. The predictions of the model find support in union certification elections data for 1977-2007 matched with data on establishment characteristics. Two selection effects emerge: unions target larger and more productive establishments early in their life-cycles, and, conditional on targeting, unions are more likely to win elections in smaller and less productive establishments.