Distributing The Gains From Trade With Incomplete Information

We argue that the incomplete information which the government has about domestic agents means that tariffs become an optimal instrument to protect them from import competition. Using a model where agents have private information about their endowments, we solve for the optimal government policy subject to the political constraint of ensuring Pareto gains from trade, the incentive compatibility constraint, and the government's budget constraint. We find that the optimal policy takes the form of nonlinear tariffs. These tariffs are never complete, in the sense of bringing prices back to their initial level, but always allow some individuals to be strictly better off than at the initial prices.