The Downstream Impact of Upstream Tariffs: Evidence from Investment Decisions in Supply Chains
研究美国制造业企业如何因供应商行业的关税削减而增加投资，发现上游关税降低10%可使下游投资增长4%至6%，且这一效应源于成本降低而非技术溢出。
Abstract We study how U.S. manufacturing firms’ investment responds to tariff reductions in supplier industries. Our estimates, based on tariff reductions following multinational trade agreements, suggest that a hypothetical 10% reduction of all upstream tariffs would increase downstream investment by 4% to 6%. This estimate is not explained by decreasing uncertainty and stems from tariff reductions for homogeneous and low-R&D inputs, consistent with the investment response resulting from cost reductions rather than superior foreign technology embodied in imported inputs. Evidence from an instrumental variable estimation using the sudden increase in Chinese import penetration suggests that import competition also increases downstream investment.