Does common ownership raise antitrust concerns?

Common ownership has raised growing antitrust concerns. We compile a comprehensive dataset of U.S. antitrust litigation cases from the Federal Trade Commission, the Department of Justice, and consumer-initiated lawsuits to shed light on these concerns. We find no robust relationship between common ownership of firm-pairs and the likelihood of these firms being jointly sued. Furthermore, common ownership is negatively associated with potential channels of collusion, such as interlocking directors and competitor-benchmarked executive pay. Evidence from institutional mergers and S&P 500 additions of rival firms supports our main conclusions. Overall, our results offer little support for the view that common ownership promotes explicit collusion.