Abstract: The complexity，severity and uncertainty of the international environment are on the rise，and the external environment exerts a more adverse impact on Chinas development To optimize structure of foreign trade，it is important to explore the factors affecting the export product mix of multiproduct enterprises Key industrial policies provide impetus for enterprises to adjust the export product mix and optimize the allocation of internal resources This study examines the influence mechanism of key industrial policies on the internal resource allocation of enterprises，explores the moderating effect of market competition，and further verifies the spillover effect of policies This paper helps to clarify the impact of key industrial policies on the adjustment of enterprises' export product mix，and explores effective ways to help export enterprises to be competitive in the international market
Key industrial policies affect the allocation of market factors by means of information transmission，make up for market failures caused by technological innovation externalities，encourage multiproductenterprises to obtain lowercost factor resources in broader channels，alleviate the cost constraints faced by enterprises entering export markets，and increase the capital investment for R&D innovation and product upgrading Industry policies stimulate the internal motivation of enterprises to improve technological innovation and cultivate new competitive advantages In addition，the decisive role of the market and the guiding role of the government work together in resource allocation As one of the incentive mechanisms provided by the market environment，market competition will also influence the effect of key industrial policies on the export product mix of multiproduct enterprises And the paper empirically tests the influences above
The study reveals several findings： Firstly，key industrial policies can promote the concentration of export product and the expansion of export product scope of multiproduct enterprises This conclusion is still valid after a series of tests，such as endogeneity tests，replacing the explanatory variables and the explained variable，and controlling the higherorder fixed effects，which proves the robustness and reliability of the conclusion Secondly，in the test of the influence mechanism，key industrial policies can not only stimulate the technological innovation of enterprises，but also alleviate the internal and external financial constraints on enterprises，so as to prompt multiproduct enterprises to adjust their export product mix Thirdly，this paper divides multiproduct enterprises into different groups according to property rights nature，trade mode and geographical location，explores the impact of key industrial policies on the adjustment of export product mix of different enterprises，and finds heterogeneity in the effects Fourthly，this paper further examines the moderating effect of market competition on the relationship between industry policies and adjustment of export product mix，and finds the more competitive the markets，the stronger the effect of key industrial policies on the export product mix Fifthly，the expansion analysis explores the impact of key industrial policies on nontargeted enterprises，and finds that industrial policies drive those enterprises of the same twodigit code industry to adjust export product mix via the spillover effect
The findings have important implications for formulating and implementing key industrial policies，actively responding to the changes of external demand and pursuing highquality development of foreign trade It is necessary to promote the coordination between key industrial policies and market mechanisms to build a modern industrial system Coping with external shocks and dispersing the rising risks of the external environment，it is important to pay attention to the role of enterprises in adjusting export product mix，which can improve the efficiency of internal resource allocation of enterprises，and pursue export progress while ensuring stability

Key words: key industrial policy, multiproduct enterprise, export product mix, resource allocation

摘要： 本文利用中国工业企业数据和海关数据，考察了重点产业政策对多产品企业出口产品组合调整的影响。研究结果发现，重点产业政策促进了企业出口产品集中度的提高和出口产品范围的扩大。这种促进作用在民营企业、外资企业、一般贸易企业和东部地区企业中更为突出。重点产业政策通过缓解企业融资约束和激励企业技术创新等渠道影响企业出口行为的调整，同时，激烈的国内同业竞争和目的地市场竞争进一步强化了产业政策效应。除了影响受支持企业的出口行为，重点产业政策还能通过融资和创新的溢出效应带动相同二位码行业内非重点企业调整出口产品组合，培育其竞争优势。

关键词: 重点产业政策, 多产品企业, 出口产品组合, 资源配置