当关税扰乱全球供应链时

中文摘要

我们在存在企业间供应关系的情境下研究未预期到的关税。企业开展成本高昂的搜寻，并与匹配生产率超过保留水平的潜在供应商进行谈判。全球供应链在自由贸易的预期下形成。随后，本国政府出人意料地征收投入品关税。这可能导致企业与原有供应商重新谈判，或搜寻替代供应商。我们校准模型参数，使其与初始进口份额以及对美国向中国加征关税所引发反应的估计结果相匹配，发现总体福利损失相当于GDP的0.12%，其中投入品采购变化和搜寻成本的贡献较大。（JEL D72、F13、F14、L14、O19、P33）

Abstract

We study unanticipated tariffs in a setting with firm-to-firm supply relationships. Firms conduct costly searches and negotiate with potential suppliers that pass a reservation level of match productivity. Global supply chains form in anticipation of free trade. Then, the home government surprises with an input tariff. This can lead to renegotiation with initial suppliers or search for replacements. Calibrating the model’s parameters to match initial import shares and the estimated responses to the US tariffs imposed on China, we find an overall welfare loss of 0.12 percent of GDP, with substantial contributions from changes in input sourcing and search costs. (JEL D72, F13, F14, L14, O19, P33)