The purpose of this paper is to study how related variety influences firm sales. We apply an instrumental variable method (as well as the most recent plausible instrumental variable method in robustness tests) to analyze more than 600,000 firm observations in all of Japan's 47 prefectures. We find that related variety, as a kind of regional industrial structure, has a U-shaped relationship with firm sales. This finding enriches the related variety perspective by supplementing micro-level evidence, revealing that the “related variety–firm sales” relationship is not linear, as most prior studies have suggested.

中文翻译：

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解开相关品种与企业销量的 U 型关系：来自日本的证据

本文的目的是研究相关品种如何影响公司销售。我们应用工具变量法（以及稳健性检验中最新的似是而非的工具变量法）分析了日本所有 47 个县的 600,000 多个公司观察。我们发现相关品种作为一种区域产业结构，与企业销售额呈U型关系。这一发现通过补充微观层面的证据丰富了相关品种的观点，揭示了“相关品种-公司销售”的关系不是线性的，正如大多数先前的研究所表明的那样。