Trade and Market Power in Product and Labor Markets

This paper studies the effects of endogenous firm-level market power in input and product markets on equilibrium prices and wages as well as the gains from trade using a general equilibrium model with heterogeneous firms. Firm-level prices and wages are functions of two endogenous distortions: (i) a markup of price over marginal cost that depends on product market shares and (ii) a markdown of wages relative to marginal revenue product that depends on labor market shares. Both distortions cause large firms to be too small relative to local labor market competitors compared to a setting with perfect competition in input and product markets. Opening product markets up to trade reallocates market shares in product and labor markets towards countries' large firms, which can reduce misallocation but also increases the labor market power of these firms. After estimating the structural parameters of the model using Indian plant-level data, I show that accounting for endogenous labor market power implies only small welfare losses due to misallocation and therefore a negligible increase in the gains from trade. Trade has significantly larger effects on firms' markups than on their markdowns. Nevertheless, because of the increase in large firms' input market power, there is a redistribution of the gains from trade from wages to firm profits.