Trade policy under monopolistic competition with firm selection

We analyze unilateral, efficient and Nash trade policies in a symmetric, two-country version of the Melitz-Ottaviano (2008) model. Starting at global free trade, we show that a country gains from the introduction of (1) a small import tariff; (2) a small export subsidy, if trade costs are low and the dispersion of productivities is high; and (3) an appropriately combined small increase in its import and export tariffs. The welfare of its trading partner, however, falls in each of these three cases. The market may provide too little or too much entry, depending on a simple relationship among model parameters. Correspondingly, global free trade is generally not efficient, even within the class of symmetric trade policies. We also provide conditions under which, starting at the symmetric Nash equilibrium, countries can mutually gain by exchanging small reductions in import tariffs, export tariffs or combinations thereof. More generally, we show that Nash equilibria are inefficient while "politically optimal" policies are efficient, indicating a central role for the terms-of-trade externality. We also discuss why the model's implications for the treatment of export subsidies in trade agreements differ from those that obtain in a model with CES preferences for the differentiated-goods sector. (C) 2020 Elsevier B.V. All rights reserved.