题目：The Benefits of Collusion: Trademark Similarity and Comovement Performance
Firms are different but also similar. I construct a novel measure of firm-by-firm pairwise trademark similarity to capture product market overlap. I find empirical support for the similarity-comovement relation: (1) trademark similarity can positively predict future profitability correlation; (2) trademark similarity is associated with higher comovement of excess return, and it is more pronounced among firm pairs with indirect industry linkages, high advertising expenses, and large growth stocks in the long term; (3) a possible explanation is proposed: firms tend to collude with their peers by adopting similar corporate actions so as to realize economies of scale while sharing potential risks, as reflected in higher cost efficiency, higher operational profitability, and lower risk exposure. Overall, firms are rivals but also friends.
杨易铭，香港大学经济与工商管理学院金融学在读博士，研究领域为实证资产定价、技术创新研究、媒体与金融市场以及金融计量应用，其论文曾获第二届中国财务与会计学术年会的最佳论文奖，以及光华金融学国际研讨会的最佳论文奖，并正在Journal of Financial and Quantitative Analysis(JFQA)审稿。