Endogenous domestic market structure and the effects of a trade cost reduction in a unionised industry

In contrast to the existing partial equilibrium literature considering the effects of a trade cost reduction on unionised wage under a given market structure, we show the effects by determining the domestic market structure endogenously. A lower trade cost reduces the number of active domestic firms, but it increases unionised wage in the active domestic firms under decentralised unions. Although a lower trade cost increases wage in the active domestic firms, it reduces domestic employment and total union utility at the free entry equilibrium. So, a trade cost reduction benefits domestic employed workers by increasing the unionised wage, but its effect on the total domestic workers is not favourable. If there is a centralised union, a lower trade cost reduces the number of active domestic firms, unionised wage, domestic employment and union utility.