We examine the impact of mergers on default risk. Despite the potential for asset diversification, we find that, on average, a merger increases the default risk of the acquiring firm. This result cannot solely be explained by the tendency for generally safe acquirers to purchase riskier targets or by the tendency of acquiring firms to increase leverage post-merger. Our evidence suggests that managerial motivations may play an important role. In particular, we find larger merger-related increases in risk at firms where CEOs have large option-based compensation, where recent stock performance is poor, and where idiosyncratic equity volatility is high. These results suggest that the increased default risk may arise from aggressive managerial actions affecting risk enough to outweigh the strong risk-reducing asset diversification expected from a typical merger.

In the 1980s, U.S. banks became systematically less profitable and riskier as nonbank competition eroded the profitability of banks' traditional activities. Bank failures rose exponentially during this decade. The leading explanation for the persistence of these trends centers on fixed-rate deposit insurance: the insurance gives bank equityholders an incentive to take on risk when the value of bank charters falls. We propose and test an alternative explanation based on corporate control considerations. We show that managerial entrenchment played a more important role than did the moral hazard associated with deposit insurance in explaining the recent behavior of the banking industry.