【摘要】 本文利用2015—2022年上市公司相关数据和美国商务部公布的出口管制实体清单名录，深入探讨了美国出口管制措施对中国企业供应链调整的影响。研究发现：(1)为应对出口管制，众多企业采取了供应链多元化策略。虽然这种策略在短期内造成了外部供应链创新水平的下降，但同期国内供应链创新度的提升对此进行了有效弥补。(2)面对外部创新产品供给的短缺，加强自主研发成为企业寻求突破的有效途径。(3)网络搜寻效率较高、获得较高补贴以及高新技术企业更可能采取多元化策略，但对于专业化程度高、供应商网络中心度大的企业，高昂的转换成本可能成为其多元化策略的绊脚石。(4)出口管制的影响存在“传导效应”,会促使受管制企业的同行业竞争者、技术同群企业以及下游企业实施多元化策略。(5)相较于未直接受影响的企业，受管制企业在经营绩效上普遍受到负面影响，提升供应链效率成为缓解这一不利影响的可行途径。更多还原

【Abstract】 In recent years, U.S. export controls have triggered a deep restructuring of global supply chains. In particular, the post-2018 strengthening of Entity List sanctions has markedly increased the uncertainty faced by Chinese strategic high-tech firms in semiconductors, 5G, and artificial intelligence. In this context, our paper employs a multi-period difference-in-differences design to empirically examine how sanction shocks have reshaped the upstream sourcing, innovation strategies, and operating performance of Chinese listed firms.The results show that affected firms significantly increase the number of total suppliers and are more likely to allocate new relationships to economies with which they have signed trade agreements or with relatively close institutional proximity. At the same time, these firms increase the number of domestic Chinese suppliers. This spatial and institutional reallocation helps circumvent regulatory “chokepoints” and reduce supply-chain risks. Regarding innovation, there is a rebalancing phenomenon that external supply-chain innovativeness declines in the short term, but that increases in the innovativeness of domestic supply chains and in firms’ internal R&D spending provide an effective offset.In addition, the resilience gains from supplier diversification are contingent on specific structural conditions. A firm’s search capability is a prerequisite for successful diversification, while switching costs pose a short-term financial barrier. Reconfiguring supply chains entails substantial switching costs that directly affect a firm’s ability and willingness to absorb diversification adjustments in the near term. When confronted with large switching-cost shocks, government subsidies play a critical role as external financing support and risk buffer, enabling firms to overcome short-term obstacles and initiate diversification. High-tech firms-as primary targets of the U.S. Entity List-have an even greater need to implement diversification strategies to mitigate potential technology-related risks. An increase in the number of U.S. firms within indirect supply relationships may reduce the number of suppliers available to firms facing technology embargoes.Sanctions also have network spillover effects. Technology peer firms and upstream and downstream partners engage in “preventive diversification” with the upstream-to-downstream transmission being more pronounced.Finally, this paper finds that the impact of export controls on firm performance exhibits a “two-stage” pattern. In the short term, due to rising costs of search, certification, and coordination, along with the use of suboptimal substitute components, corporate operating performance deteriorates. In the medium term, if firms can combine diversification strategies with improvements in supply-chain efficiency, the negative effects diminish significantly and the pace of recovery accelerates, facilitating performance restoration.Based on these findings, this paper proposes the following policy recommendations. Externally, it is essential to complete a network of high-standard free-trade agreements, prioritizing cooperation with countries with similar institutional frameworks and complementary technologies. Domestically, high-tech firms subject to controls should lead the formation of innovation consortia with high-potential suppliers and research institutions, focusing on bottleneck segments and providing targeted R&D subsidies. Simultaneously, a risk-warning and joint-response platform should be built to enhance the efficiency of searching for and matching substitute suppliers. Firms hindered by high specificity and network concentration should receive low-interest loans and subsidies to help them overcome sunk costs, adjust technological paths and processes, and rebuild more resilient supply chains.The contributions of this paper are threefold. First, drawing on micro-level supplier-customer relationships, it provides direct evidence that under export controls, Chinese listed firms reconstruct upstream networks through spatial reallocation and source substitution. Second, it depicts the vertical asymmetry in how shocks propagate along technology peer groups and value chains, offering new perspectives on policy spillovers and systemic risk. Third, it shows that rapid diversification does not necessarily lead to persistent performance losses: as long as diversification is coupled with improvements in supply-chain efficiency, firms can achieve a balance between risk and efficiency in the medium term. Future research should refine supplier substitution processes by considering product-technology complexity, clarify the characteristics of substitute products, and incorporate factors such as product quality and logistics friction into structural assessments. This would enable more precise quantification of the risk-efficiency trade-offs of rapid diversification, providing more actionable guidance for industrial policy and corporate strategy.更多还原