Empirical evidence suggests that the bargaining power of trade unions differs across firms and sectors. Standard models of unionization ignore this pattern by assuming a uniform bargaining strength. In this paper, we incorporate union heterogeneity into a Melitz (2003) type model. Union...

Empirical evidence suggests that high-productivity firms face stronger trade unions than low-productivity firms. Then a policy that puts all unions into a better bargaining position is no longer neutral for firm selection as in models with a uniform bargaining strength across firms. Using a...