Union status and merger activity in the U.S.

Theories on merger activity and union membership suggest that conglomerate mergers should enhance the probability of managers employing nonunion workers, while nonconglomerate mergers should be associated with a greater probability of union membership. To test this hypothesis, a standard sample-selection derived union status equation is estimated which includes measures of three types of merger activity as explanatory variables. The findings suggest that being in an industry with substantial conglomerate mergers reduces the chance that a worker is a union member. All other types of mergers are positively associated with the probability of union membership. This pattern holds even after controlling for the possibility of merger endogeneity.