We analyze a unionized duopoly model to examine how unions affect the incentives for merger. We find that, once the union has the option to delegate, an increase in the union bargaining power can create incentives for the firms to merge.

We develop a model of wage determination with private information, in which te union has the option to delegate the wage bargaining to either surplus-maximizing delegates or to wage-maximizing delegates (such as senior union members). We show that the strike activity is greater whenever the...