This study examines how antitrust law adoptions affect horizontal merger and acquisition (M&A) outcomes. Using the staggered introduction of competition laws in 20 countries, we find antitrust regulation decreases acquirers’ five-day cumulative abnormal returns surrounding horizontal merger announcements. A decrease in deal value, target book assets, and industry peers' announcement returns are consistent with the market power hypothesis. Exploiting antitrust law adoptions addresses a downward bias to an estimated effect of antitrust enforcement (Baker (2003)). The potential bias from heterogeneous treatment effects does not nullify our results. Overall, antitrust policies seem to deter post-merger monopolistic gains, potentially improving customer welfare.

We present causal evidence on the effect of boardroom networks on firm value and compensation policies. We exploit a ban on interlocking directorates of Italian financial and insurance companies as exogenous variation and show that firms that lose centrality in the network experience negative abnormal returns around the announcement date. The key driver of our results is the role of boardroom connections in reducing asymmetric information. The complementarities with the input-output and cross-ownership networks are consistent with this channel. Using hand-collected data, we also show that network centrality has a positive effect on directors’ compensation, providing evidence of rent sharing.

We observe that public firms are more likely to issue seasoned stocks rather than bonds when theirs boards are more socially-connected. These connected issuers experience better announcement-period stock returns and attract more institutional investors. This social-connection effect is stronger for firms with severe information asymmetry, higher risk of being undersubscribed, and more visible to investors. Our conjecture is this social-network effect is driven by trust in issuing firms. Given stocks are more sensitive to trust, these trusted firms are more likely to issue stocks than bonds. Trustworthiness plays an important role in firms’ security issuances in capital markets.

We estimate how US state courts impact firm value by exploiting a US Supreme Court ruling that exogenously changed firms’ exposure to different courts. We find that increased exposure to more business-friendly courts is associated with positive announcement returns. We find no such association for objective court quality. Consistent with the ruling impacting firm value through the legal environment channel, we find that effects are stronger for firms with high litigation exposure. We find that the ruling led to a shift in both the geographic distribution of lawsuits and operations of firms.

This paper examines the effect of credit rating disagreements on merger and acquisition (M&A) decisions. We show that acquirers with split ratings prefer to use stock to finance their acquisitions. More importantly, we find that acquirers with split ratings experience lower announcement returns. Further analysis shows that overpayment by acquirers with split ratings is concentrated in acquirers with entrenched managers. Our results are robust to alternative identification strategies. Overall, our evidence indicates that credit rating disagreements are heavily priced in the M&A market.