ABSTRACT We present a simple, yet powerful, battery of univariate and panel unit root tests on market shares to draw some inferences regarding the level of rivalry within an industry. As an application, we employ them on the Japanese tire industry over a 40-year period. We find that rivalry seems to be present among the smaller firms, while at the same time, the dominant firm seems unperturbed by the competition. We compare these conclusions with a previous study of the industry.

中文翻译：

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使用市场份额分析的日本轮胎行业市场竞争的新证据

摘要我们针对市场份额提出了一种简单而强大的单变量和面板单元根检验，以得出有关行业竞争水平的一些推论。作为一种应用，我们在日本轮胎行业使用了40年。我们发现较小的公司之间似乎存在竞争，而与此同时，主导公司似乎不受竞争的干扰。我们将这些结论与该行业的先前研究进行比较。