Event studies examine stock price movements around corporate events. These events can be voluntary firm announcements (e.g., new product introduction, alliance formation, channel restructuring) or announcements made by other entities such as regulatory bodies (e.g., FDA approval) or competitors (e.g., new market entry). The event study methodology was developed by finance researchers but has been widely adopted in other fields, including marketing. We review the manner in which event studies have been used in the marketing literature and summarize the current state of knowledge about the design and interpretation of event studies. We provide guidelines for researchers who use this methodology and for readers who draw inferences from results obtained from event studies, and we highlight a few areas where the methodology can be leveraged to help us better understand the financial value of marketing actions. Keywords Event study . Stock returns . Abnormal stock performance . Corporate announcements . Financial value of marketing actions 1 A smaller stream of literature examines long-term abnormal returns to events. We also review that literature and the methods that underlie it.J. Andrew Petersen served as Area Editor for this article.

Well-known brands are frequently imitated, misused, or tampered with. Firms facing these threats routinely turn to the legal system and file trademark infringement lawsuits in an attempt to prevent revenue losses and brand equity dilution. In this article, the authors address the largely unexplored issue of brand protection. First, they categorize all major types of trademark infringement. Second, using signaling and prospect theories, they present a conceptual model that outlines the financial consequences of defending a brand in court. The authors test the predictions of this framework using a large sample of trademark infringement lawsuits and find that although investors react negatively in the short term to firms’ filing and even to firms’ winning such cases, the long-term performance of firms that successfully leverage the legal system to protect their brands is positive.