Data and Code for "Tariffs and Goods-Market Search Frictions"

We study tariffs in a general equilibrium dynamic model with search frictions between heterogeneous exporting producers and importing retailers. We show the model has a unique equilibrium and analytically characterize home unilateral import tariffs that maximize welfare given a passive foreign country. Search frictions add two terms to the standard optimal tariff expression: One lowers tariffs when contact rates are low; another when private export costs exceed social opportunity costs. Search frictions also introduce new incentives to subsidize imports due to market thickness effects. We calibrate our baseline to U.S. and Chinese 2016 data. We compare this baseline to a counterfactual with international search costs reduced to domestic levels but with all other parameters fixed. We find that higher baseline search costs reduce optimal U.S. unilateral and Nash tariffs and attenuate welfare responses to tariff changes.本文研究异质性出口生产商与进口零售商之间存在搜寻摩擦（Search frictions）的一般均衡动态模型中的关税问题。我们证明该模型存在唯一均衡，并解析刻画了在外国经济体保持被动的前提下，实现福利最大化的本国单边进口关税。搜寻摩擦为标准最优关税表达式增添了两项调整项：其一在接触率较低时降低关税水平；其二在私人出口成本高于社会机会成本时发挥作用。此外，搜寻摩擦还因市场厚度效应催生了进口补贴的新激励。我们将基准模型校准至2016年中美两国数据，并将该基准情景与另一反事实情景进行对比：后者将国际搜寻成本降至国内水平，同时保持其余参数固定不变。研究发现，更高的基准搜寻成本会降低美国单边最优关税与纳什关税（Nash tariffs），并削弱关税变动引发的福利响应。