【摘要】 在外部需求不确定性加剧的情况下，如何实现出口产品质量升级是中国新发展阶段的重要议题。文章在异质性企业模型基础上内生化产品质量构建理论模型，从微观视角揭示了外部需求变动对多产品企业出口产品质量的影响及其机制。基于中国微观企业数据的实证研究表明，外部需求扩张有利于出口产品质量升级，但该升级效应随产品排序的提高而减弱。机制分析可得，外部需求扩张通过规模效应和竞争效应正向和负向影响出口产品质量，规模效应和竞争效应分别随产品排序的提高而弱化和强化。为应对外部需求冲击，中国多产品企业采取质量竞争的核心产品策略，优化企业资源配置，促进出口产品质量升级。文章为中国多产品企业有效应对外部需求变动和推动中国贸易强国建设提供了理论依据和政策启示。更多还原

【Abstract】 Given the increasing uncertainty in external demand, how to achieve the upgrading of export product quality is an important issue in China’s new development stage. This paper constructs a theoretical model by endogenizing product quality based on the heterogeneous enterprise model and reveals the impact and mechanism of external demand changes on export product quality of multi-product enterprises from the micro perspective. The empirical research based on China’s micro-enterprise data shows that external demand expansion is conducive to the upgrading of export product quality, but this upgrading effect weakens as product ranking rises. The mechanism analysis reveals that external demand expansion has a positive impact on export product quality through the scale effect and has a negative impact on export product quality through the competition effect, while the scale effect strengthens and the competition effect weakens with the rise of product ranking respectively.To cope with external demand shocks, China’ s multi-product enterprises adopt the core product strategy of quality competition and optimize resource allocation of the enterprises to promote the upgrading of export product quality. This paper provides the theoretical basis and policy implications for China’ s multi-product enterprises to effectively respond to external demand changes and for China to build itself into a trade powerhouse.更多还原