We derive a small open economy (SOE) as the limit of an economy as the number or size of its trading partners goes to infinity and trade costs also go to infinity. We obtain this limit in the Armington, Eaton-Kortum, Krugman, and Melitz models. In all cases, the trade of the SOE with the foreign...

We study the optimal trade policy against a foreign oligopoly withendogenous quality. We show that, under the Most Favoured Nation(MFN) clause, a uniform tariff policy is always welfare improvingover the free trade equilibrium. However, a nonuniform tariff policyis always desirable on welfare...