CAN THE OPTIMAL TARIFF BE ZERO FOR A GROWING LARGE COUNTRY?
扩展了Rivera-Batiz-Romer实验室设备模型，引入不对称国家和进口关税，发现单边关税削减总能提高平衡增长率，且在温和条件下零关税是局部最优。
Abstract Can the optimal tariff be zero for a growing large country? To pursue the possibility, we extend the Rivera‐Batiz–Romer lab‐equipment model of endogenous technological change to include asymmetric countries, import tariffs, and either homogeneous or heterogeneous firms. Each country's domestic revenue share is a sufficient statistic for its long‐run growth rate, but it is not for its long‐run welfare. A unilateral tariff reduction by either country always increases the balanced growth rate. A zero tariff is locally optimal for a country under a mild condition, which is automatically satisfied at a symmetric balanced growth path with the zero tariff.