Thesis advisor: Philp E. Strahan / This dissertation is comprised of three essays which examine the interactions among credit market innovation, corporate finance, and information intermediaries. In the first essay, I study the role of credit default swaps (CDS) in reducing credit supply frictions for corporate borrowers. I find that firms whose CDS is included in a major CDS index--the CDX North American Investment Grade index--have significantly lower cost of debt, and in response rely more heavily on debt for external financing. To address the potential endogeneity of index addition, I use a regression discontinuity design by exploiting the index inclusion rule, which allows me to compare firms that are just above and below the index inclusion cutoff. I show that index inclusion improves the liquidity of underlying single-name CDSs, which enables constituent firms' debtholders to better hedge their credit risk exposure. My findings suggest that CDS market benefits investment-grade borrowers by alleviating the supply-side frictions in credit markets. In the second essay, we investigate the role of proxy advisory firms in shareholder voting. Proxy advisory firms have become important players in corporate governance, but the extent of their influence over shareholder votes is debated. We estimate the effect of Institutional Shareholder Services (ISS) recommendations on voting outcomes by exploiting exogenous variation in ISS recommendations generated by a cutoff rule in its voting guidelines. Using a regression discontinuity design, we find that in 2010-2011, a negative ISS recommendation on a say-on-pay proposal leads to a 25 percentage point reduction in say-on-pay voting support, suggesting strong influence over shareholder votes. We also use our setting to examine the informational role of ISS recommendations. In the third essay, I examine how Moody's ratings have responded to the introduction of Credit Default Swap (CDS) market--an important innovation in credit markets in the past decade. I find that ratings quality of CDS firms, measured as default predictive power, improved significantly after the onset of CDS trading, consistent with a disciplining role of the CDS market. I show that ratings become more accurate in terms of less failure to warn (i.e. rating a defaulter too high) which is not accompanied by a rise of false alarms. In addition, rating downgrades are significantly more likely to be preceded by negative outlook or a watch for downgrade. The results are robust to controlling for the endogeneity of CDS trading. Overall, the evidence suggests that, in response to the CDS market developments, Moody's ratings become better at differentiating bad issuers from good ones as opposed to a "cookie-cutter'' approach to more conservative ratings. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Carroll School of Management. / Discipline: Finance.