Event studies are an important tool for empirical research in Finance. Since the seminal contribution of Fama et al. [Fama, E., Fisher, L., Jensen, M., Roll, R., 1969. The adjustment of stock prices to new information. International Economic Review 10, 1–21], there have been many enhancements to the classical test methodology. Somewhat surprisingly, the estimation period has attracted less interest. It is usually routinely determined as a fixed window prior to the event announcement day. In this study, we propose a test that reduces the impact of potentially unrelated events during the estimation period. Our proposition is based on a two-state version of the classical market model as a return-generating process. We present standard specification and power analyses. The results highlight the importance of explicitly controlling for unrelated events occurring during the estimation window, especially in the presence of event-induced increase in return volatility.

Mergers and acquisitions offer a framework for shedding new light on the stock market performance of socially responsible investments (SRI). We use Innovest’s Intangible Value Assessment (IVA) ratings as a measure of firms’ ability to cope with social and environmental risks. The IVA ratings allow us to uncover a positive relation between acquirer gains and the level of the target’s social and environmental risk management practices. Our findings suggest that the stock market rewards the acquirer for making socially and environmentally responsible investments. We also document that the environmental and social performance of the acquirer increases following the acquisition of a SRI aware target. These results are consistent with acquirer learning from the target’s SRI practices and experiences.

Does legal insider trading contribute to market efficiency? Using refinements proposed in the recent microstructure literature, we analyzed the information content of legal insider trading. We used data on 2110 companies subject to 59,244 aggregated daily insider trades between January 1995 and the end of September 1999. Our main finding is that, even though financial markets do not respond strongly in terms of abnormal returns to insider trading activities, the significant change in price sensitivity to relative order imbalance due to abnormal insider trades reveals that price discovery is hastened on insider trading days.

To protect inframarginal rents, rivals react to competition shocks by increasing product differentiation or lowering costs by standardizing products and production processes. We test these two mutually exclusive reactions by exploiting changes in rivals’ idiosyncratic stock return comovement following significant tariff cuts. While increased product differentiation implies a reduction in return comovement, greater standardization implies the opposite (a comovement increase). Difference-in-differences (DID) tests indicate that tariff cuts cause a significant increase in return comovement—in particular among within-industry “followers.” Treatment effects on cash flows, product counts, similarity scores, and business segment counts further support cost-cutting strategies.

Cross-border merger activity is growing in importance. We map the global trade network each year from 1989 to 2016 and compare it to cross-border and domestic merger activity. Trade-weighted merger activity in trading partner countries has statistically and economically significant explanatory power for the likelihood that a given country will be in a merger wave state, at both the cross-border and domestic levels, even controlling for its own lagged merger activity. The role of trade as a channel for transmitting merger waves is confirmed using import tariff cuts and trade sanctions as instruments to mitigate endogeneity. Overall, the full trade network helps our understanding of merger waves and how merger activity propagate across borders.

Chief executive officer (CEO) narcissism affects the takeover process. Acquirer shareholders react less favorably to a takeover announcement when the target CEO is more narcissistic. Narcissistic acquiring CEOs negotiate faster. They are also marginally more likely to initiate deals. Acquirer CEO narcissism and target CEO narcissism are associated with a lower probability of deal completion and reduce the likelihood that the target CEO will be employed by the merged firm. Our findings highlight the importance of both acquirer and target CEO psychological characteristics throughout the takeover process.

During 1992–2007, suppliers financed almost 10% of the total assets of US listed firms. This intensive usage of trade credit is puzzling in the light of its high (implicit) costs. By arguing that trade credit use provides valuable information to outside investors, we first derive a theoretical model that predicts a positive correlation between trade credit use and the quality of the firm’s investments. Then, using several proxies for firm’s investment quality (Z-score, return on assets, and long-run abnormal returns), we show that this prediction receives strong support from a large sample of US firms.