Firm Heterogeneity and Credit Risk Diversification

This paper considers a simple model of credit risk and derives the limit distribution of losses under different assumptions regarding the structure of systematic and idiosyncratic risks and the nature of firm heterogeneity. The theoretical results obtained indicate that if firm-specific risk exposures (including their default thresholds) are heterogeneous but come from a common parameter distribution, for sufficiently large portfolios there is no scope for further risk reduction through active credit portfolio management. However, if the firm risk exposures are draws from different parameter distributions, say for different sectors or countries, then further risk reduction is possible, even asymptotically, by changing the portfolio weights. In either case, neglecting parameter heterogeneity can lead to underestimation of expected losses. But, once expected losses are controlled for, neglecting parameter heterogeneity can lead to overestimation of risk, whether measured by unexpected loss or value-at-risk. The theoretical results are confirmed empirically using returns and credit ratings for firms in the U.S. and Japan across seven sectors. Ignoring parameter heterogeneity results in far riskier credit portfolios.risk management, correlated defaults, heterogeneity, diversification, portfolio choice

Mortgage Convexity

Most home mortgages in the U.S. are fixed-rate loans with an embedded prepayment option. When long-term rates decline, the effective duration of mortgage-backed securities (MBS) falls due to heightened refinancing expectations. I show that these changes in MBS duration function as large-scale shocks to the quantity of interest rate risk that must be borne by professional bond investors. I develop a simple model in which the risk tolerance of bond investors is limited in the short run, so these fluctuations in MBS duration generate significant variation in bond risk premia. Specifically, bond risk premia are high when aggregate MBS duration is high. The model offers an explanation for why long-term rates may appear to be "excessively sensitive" to movements in short rates and explains how changes in MBS duration act as a positive-feedback mechanism that amplifies interest rate volatility. I find strong support for these predictions in the time series of U.S. government bond returns

Factors Affecting Student Loan Default in Proprietary Non-Degree Granting Colleges

The significant problem addressed in this research was the increasing default rate among federal student loan borrowers who attended non-degree-granting proprietary colleges in Florida (i.e., career and technical colleges). The purpose of this study was to identify, better understand, and predict which borrower characteristics increased the likelihood of student loan default at proprietary non-degree-granting colleges. The research was based on the structural-functional and planned behavior theories and utilized a quantitative, non-experimental, cross-sectional design to explore the relationship between academic success, age, college graduation status, ethnicity, gender, high school class ranking, and federal student loan default. Self-reported data were obtained from students who attended private, for-profit, less than 2-year colleges in Florida. To determine which student borrower characteristics predicted an increase in the likelihood that borrowers would default on their student loan payments, one hypothesis was proposed to evaluate six borrower characteristics. Logistic regression analysis was used to explore the statistical relationships and found that academic success, age, and gender were statistically significant in predicting student loan default among students who attended private, for-profit, less than 2-year colleges in Florida. This study may facilitate positive social change by aiding educational institutions in identifying at-risk borrower characteristics and by providing various default prevention strategies that could be incorporated into specific counseling messages to reduce future student loan defaults and lower institutional cohort default ratings

Characteristic Timing

We use differences between the attributes of stock issuers and repurchasers to forecast characteristic-related stock returns. For example, we show that large firms underperform following years when issuing firms are large relative to repurchasing firms. Our approach is useful for forecasting returns to portfolios based on book-to-market (HML), size (SMB), price, distress, payout policy, profitability, and industry. We consider interpretations of these results based on both time-varying risk premia and mispricing. Our results are primarily consistent with the view that firms issue and repurchase shares to exploit time-varying characteristic mispricing.

Monetary Policy and Long-Term Real Rates

Changes in monetary policy have surprisingly strong effects on forward real rates in the distant future. A 100 basis point increase in the two-year nominal yield on a Federal Open Markets Committee announcement day is associated with a 42 basis point increase in the ten-year forward real rate. This finding is at odds with standard macro models based on sticky nominal prices, which imply that monetary policy cannot move real rates over a horizon longer than that over which all prices in the economy can readjust. Instead, the responsiveness of long-term real rates to monetary shocks appears to reflect changes in term premia. One mechanism that could generate such variation in term premia is based on demand effects due to the existence of what we call yield-oriented investors. We find some evidence supportive of this channel

Monetary Policy and Long-Term Real Rates

Changes in monetary policy have surprisingly strong effects on forward real rates in the distant future. A 100 basis-point increase in the 2-year nominal yield on an FOMC announcement day is associated with a 42 basis-point increase in the 10-year forward real rate. This finding is at odds with standard macro models based on sticky nominal prices, which imply that monetary policy cannot move real rates over a horizon longer than that over which all prices in the economy can readjust. Rather, the responsiveness of long-term real rates to monetary shocks appears to reflect changes in term premia. One mechanism that may generate such variation in term premia is based on demand effects coming from “yield-oriented” investors. We find some evidence supportive of this channel

The Growth and Limits of Arbitrage: Evidence from Short Interest

We develop a novel methodology to infer the amount of capital allocated to quantitative equity arbitrage strategies. Using this methodology, which exploits time-variation in the cross section of short interest, we document that the amount of capital devoted to value and momentum strategies has grown significantly since the late 1980s. We provide evidence that this increase in capital has resulted in lower strategy returns. However, consistent with theories of limited arbitrage, we show that strategy-level capital flows are influenced by past strategy returns as well as strategy return volatility, and that arbitrage capital is most limited during times when strategies perform best. This suggests that the growth of arbitrage capital may not completely eliminate returns to these strategies

Are There Too Many Safe Securities? Securitization and the Incentives for Information Production

We present a model that helps explain several past collapses of securitization markets. Originators issue too many informationally insensitive securities in good times, blunting investor incentives to become informed. The resulting endogenous scarcity of informed investors exacerbates primary market collapses in bad times. Inefficiency arises because informed investors are a public good from the perspective of originators. All originators benefit from the presence of additional informed investors in bad times, but each originator minimizes his reliance on costly informed capital in good times by issuing safe securities. Our model suggests regulations that limit the issuance of safe securities in good times

Issuer Quality and Corporate Bond Returns

We show that the credit quality of corporate debt issuers deteriorates during credit booms, and that this deterioration forecasts low excess returns to corporate bondholders. The key insight is that changes in the pricing of credit risk disproportionately affect the financing costs faced by low quality firms, so the debt issuance of low quality firms is particularly useful for forecasting bond returns. We show that a significant decline in issuer quality is a more reliable signal of credit market overheating than rapid aggregate credit growth. We use these findings to investigate the forces driving time-variation in expected corporate bond returns