Between 2001 and 2007, the complexity of commercial mortgage-backed securities (CMBS) increased substantially. The median size of commercial mortgage loan pools tripled and the median number of AAA-rated tranches doubled. I examine whether deal complexity is related to loan performance by analyzing a sample of approximately 40,000 commercial mortgage loans from 334 CMBS deals. I find that loan performance is worse for loans in more complex securitizations. However, neither the price of a deal’s securities nor a deal’s risk retention reflected that complexity correlates with lower loan quality. These findings present a challenge for theories of optimal security design.

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.

This paper studies the influence of the state of the business cycle on credit ratings. In particular, we assess whether rating agencies are excessively procyclical in their assignment of ratings. Our analysis is based on a model of ratings determination that takes into account factors that measure the business and financial risks of firms, in addition to indicators of macroeconomic conditions. Utilizing annual data on all US firms rated by Standard & Poor’s, we find that ratings do not generally exhibit excess sensitivity to the business cycle. In addition, we document that previously reported findings of a secular tightening of ratings standards are not robust to a more complete accounting of systematic changes to measures of risk.