This paper examines the relationship between product market competition and intermediate-term relative strength strategies in the U.S. over the past two decades, i.e., from 1997 to 2016. As industries become increasingly concentrated, I find that return reversal patterns are observable only in competitive industries. As the industry concentration level (ICL) increases, these patterns gradually disappear and reverse in the highly concentrated industry quintile. The performance of intermediate-term relative strength strategies is affected by not only the product market competition level but also recent recessions. In the sample, I find no reliable and robust momentum effect. These results shed new light on the relationship between the product market competition levels and the performance of intermediate-term relative strength strategies.

中文翻译：

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产品市场竞争及中期动能

本文考察了美国过去 20 年（即 1997 年至 2016 年）产品市场竞争与中期相对实力战略之间的关系。随着行业越来越集中，我发现只有在竞争性行业中才能观察到回报反转模式. 随着行业集中度（ICL）的提高，这些模式在高度集中的行业五分之一中逐渐消失和逆转。中期相对强弱策略的表现不仅受产品市场竞争水平的影响，也受近期经济衰退的影响。在样本中，我没有发现可靠且稳健的动量效应。这些结果为产品市场竞争水平与中期相对强弱策略的表现之间的关系提供了新的启示。