How Unsecured Credit Policies Influence Mortgage and Unsecured Loan Defaults

Before the global financial crisis, the proportion of households defaulting on the mortgage while remaining current on the unsecured loan was almost the same as the proportion of households current on the mortgage but defaulting on the unsecured loan. After the crisis, the former ratio became higher than the latter. By using a heterogeneous agent model with the mortgage and the unsecured loan, I examine how the order of defaults changed before and after the crisis. I then analyze the impacts of unsecured credit policies on households' mortgage and unsecured loan defaults. My quantitative exercise shows that both default rates can decrease as the cost for unsecured loan defaults increases.     

House Price Markups and Mortgage Defaults

The transaction price of identical housing units can vary widely due to heterogeneity in buyer and seller preferences, matching, and search costs, generating what we term “markups” above or below the average market price. We measure markups for 3.4 million purchase-money mortgages and show that they can predict mortgage defaults and credit losses conditional on default even after accounting for collateral coverage (loan-to-value ratio) and a comprehensive set of other covariates. The findings suggest that standard collateral coverage estimation may be inaccurate, with implications for both individual and portfolio-level credit risk assessment.     

Are Commercial Mortgage Defaults Affected by Tax Considerations?

We study whether tax considerations are an important determinant of commercial mortgage default. We also study whether large lenders are better informed, or better at interpreting information for lending purposes, and hence have lower foreclosure rates; whether lenders have more information on larger borrowers than smaller borrowers, and hence have lower foreclosure rates on larger loans; and whether commercial mortgage defaults are related to debt service coverage and loan-to-values, both initial and contemporaneous. The paper’s main findings are fourfold. First, holding all else equal, there is evidence that tax considerations influence investors’ decisions about when to “put” assets to lenders. The results are consistent with the argument of Constantinides (J Financ Econ 13:65–89, 1984). Second, the evidence suggests that large lenders are especially knowledgeable about commercial mortgage borrowers and commercial property markets, in that they have lower foreclosure rates than smaller lenders. Third, on the question of whether lenders have more information on larger borrowers than smaller borrowers, we find that larger loans have, on average, lower default rates than smaller loans. Fourth, the findings suggest that lower default rates are associated with higher debt service coverage ratios, both initial and contemporaneous.     

Are CDS Auctions Biased and Inefficient?

We study the design of credit default swaps (CDS) auctions, which determine the payments by CDS sellers to CDS buyers following defaults of bonds. Using a simple model, we find that the current design of CDS auctions leads to biased prices and inefficient allocations. This is because various restrictions imposed in CDS auctions prevent certain investors from participating in the price discovery and allocation process. The imposition of a price cap or floor also gives dealers large influence on the final auction price. We propose an alternative double auction design that delivers more efficient price discovery and allocations.     

How does credit risk affect cost management strategies? Evidence on the initiation of credit default swap and sticky cost behavior

In this paper, we examine the effect of credit defaults swaps (CDS) initiation on reference firms' cost management strategies. CDS contracts provide insurance protection for creditors, inducing a shift in bargaining power from borrowers to creditors and an excessive incidence of bankruptcy. Anticipating more intransigent creditors in debt renegotiations and higher bankruptcy risk, CDS firms are incentivized to mitigate risk through decreasing cost stickiness after CDS initiation, as cost stickiness lowers liquidity and triggers early covenant violations. We find that, on average, CDS initiation is associated with a decline in reference firms' cost stickiness. This association is more pronounced for less liquid, financially distressed, and lower credit quality firms. We also find that CDS firms with a reduction in cost stickiness will exhibit lower future bankruptcy risk than CDS firms without such as reduction in stickiness. Collectively, our findings suggest that the CDS-induced “empty creditor problem” causes reference firms to undertake more conservative cost management practices to alleviate downside risk.     

An Analysis of Mortgage Termination Risks: A Shared Frailty Approach with MSA-Level Random Effects

Investigating the residential mortgage defaults and prepayments has been the subject of research for the past three decades. The literature on mortgage default and prepayment is often used to inform credit risk policies and asset pricing strategies. This literature has evolved from the use of logistic regressions to the use of survival and frailty models that control for unobserved heterogeneity. In this paper, we apply a shared-frailty survival model to analyze the mortgage termination risks. In particular, we investigate whether mortgages originated in the same Metropolitan Statistical Area (MSA) share common unobserved factors and how these factors affect the mortgage termination risks. The paper demonstrates that MSA-level frailty, together with other risk factors, has significant effects on the probability of mortgage terminations risks.     

Housing-Price Cycles and Prepayment Rates of U.S. Mortgage Pools

Empirical mortgage prepayment models generally have trouble explaining differences in mortgage-prepayment speeds among pools with similar interest rates on the underlying mortgages. In this article, we model some of the sources of termination heterogeneity across mortgage pools, particularly the role of regional variations in housing prices in generating atypical prepayment speeds. Using a sample of Freddie Mac mortgage pools from 1991 to 1998, we compare two classes of empirical models: a rational option-pricing model using a backward-solving pricing algorithm and an empirical hazard model. In both empirical estimation strategies, we find evidence that differences in house-price dynamics across regions are an important source of between-pool heterogeneity. This finding is then shown to be robust to alternative ways of parameterizing pool heterogeneity in mortgage termination models.     

Unobservable heterogeneity and rational learning: Pool-specific versus generic mortgage-backed security prices

Previous mortgage prepayment and valuation models assume that two mortgage pools with the same observable characteristics should behave indistinguishably. However, even pools with apparently identical characteristics often exhibit markedly different prepayment behavior. The sources of this heterogeneity may be unobservable, but we can infer information about a pool from its prepayment behavior over time. This article develops a methodology for using this information to calculate pool-specific mortgage-backed security prices. Knowledge of these prices is important both for portfolio valuation and for determining the cheapest pool to deliver when selling mortgagebacked securities. We find that unobservable heterogeneity between mortgage pools is statistically significant, and that pool-specific prices, calculated for a sample of outwardly identical mortgage pools between 1983 and 1989, may differ greatly from any single representative price.     

Determinants of Mortgage Default and Consumer Credit Use: The Effects of Foreclosure Laws and Foreclosure Delays

The mortgage default decision is part of a complex household credit management problem. We examine how factors affecting mortgage default spill over to other credit markets. As home equity turns negative, homeowners default on mortgages and home equity lines of credit at higher rates, whereas they prioritize repaying credit cards and auto loans. Larger unused credit card limits intensify the preservation of credit cards over housing debt. Although mortgage nonrecourse statutes increase default on all types of housing debt, they reduce credit card defaults. Foreclosure delays increase default rates for housing and nonhousing debts. Our analysis highlights the interconnectedness of debt repayment decisions.     

The Optimal Mortgage Loan Portfolio in UK Regional Residential Real Estate

In this study, we propose a method based on large deviation theory (LDT), which minimises credit risk (expected loss). We demonstrate how mortgage loan portfolios can be optimised using geographical differences in the risk characteristics of mortgage loans in the UK. Our empirical results show that credit risk can be reduced by a third when the LDT method is used instead of the benchmark portfolios that we calculate with regional-gross-value-added weights and equal weights. More importantly, the difference in the expected loss between these portfolios increases further during bearish housing markets. To see that such numbers matter, in an extreme scenario, the UK mortgage lenders could lose more than 2% a year as the consequence of mortgage defaults, which is equivalent to an annual loss of approximately 20 billion pounds in the UK. Although this extreme state would not continue for a long time, it nevertheless represents a huge potential loss for mortgage lenders and investors.     

A Proportional Hazards Model of Commercial Mortgage Default with Originator Bias

A proportional hazards model with competing risks is specified and is extended to correct for the possibility of originator bias. The model is used to examine the ability of option-theoretic models of mortgage pricing to forecast commercial mortgage defaults. Among the findings, those especially of interest include the influence of contemporaneous loan-to-value and debt-service-coverage ratios on commercial mortgage default probabilities. The paper also finds that option-theoretic models of mortgage pricing are quite capable of producing default estimates that fit the actual default rates well, especially when the model is corrected for originator bias.     

The effect of foreclosure laws on securitization: Evidence from U.S. states

A mortgage that defaults is more likely to enter foreclosure rather than renegotiation if it has been securitized in the private non-agency market, according to previous research. We study whether this foreclosure-propensity affects lenders’ securitization decision ex-ante. Due to the higher foreclosure probability, the value of a mortgage should be more sensitive to foreclosure costs if it is securitized. Comparing loans made in the same metropolitan area but under different foreclosure laws, we find that lenders are less likely to securitize mortgages in states with higher foreclosure costs, as measured by laws requiring judicial foreclosure. Two additional results are consistent with the proposed channel. First, the effect increases for loans with higher expected default rates and disappears for mortgage-like loans not subject to these laws. Second, the effect of judicial requirements increases for loans with higher expected default rates, consistent with differences in loss given default driving the results. Borrowers in states without judicial requirements also get riskier loans.     

The probability of fixed- and adjustable-rate mortgage termination

This article analyzes mortgage terminations using a national individual loan data set for the 1986–1992 period. The standard option-choice-theoretic framework is supplemented with variables to proxy for non-option-related termination determinants. Separate multinominal logit models are estimated for three mortgage types: 30-year FRMs, 15-year FRMs, and 30-year ARMs. The results indicate substantial differences in the response of the mortgage types to variables included in the model. FRM15 prepayments are the most responsive to prepayment option values; FRM30 prepayments are less responsive to option values and are dirven by local area housing market and economic conditions; ARM prepayment rates are higher but defeult rates are lower relative to the FRMs. A noteworthy finding is that teaser discounts reduce the likelihood of ARM defaults.     

A first-passage-time model under regime-switching market environment

In this paper, we suggest a first-passage-time model which can explain default probability and default correlation dynamics under stochastic market environment. We add a Markov regime-switching market condition to the first-passage-time model of Zhou [Zhou, C., 2001. An analysis of default correlations and multiple defaults. Review of Financial Studies 14, 555–576]. Using this model, we try to explain various relationship between default probability, default correlation, and market condition. We also suggest a valuation method for credit default swap (CDS) with (or without) counterparty default risk (CDR) and basket default swap under this model.Our numerical results provide us with several meaningful implications. First, default swap spread is higher in economic recession than in economic expansion across default swap maturity. Second, as the difference of asset return volatility between under bear market and under bull market increases, CDS spread increases regardless of maturity. Third, the bigger the intensity shifting from bull market to bear market, the higher the spread for both CDS without CDR and basket default swap.     

Refinance and Mortgage Default: A Regression Discontinuity Analysis of HARP’s Impact on Default Rates

This paper examines the impact of refinancing on mortgage defaults based on an empirical investigation of the Home Affordable Refinance Program (HARP). We study a unique dataset from Freddie Mac which includes loans funded right before and after the HARP eligibility cutoff date, an exogenous event. Using a Fuzzy Regression Discontinuity Design method, we show that receiving a HARP refinance decreases the expected monthly default rate by about 48–62 percent using different bandwidth specifications.     

Mortgage Default during the U.S. Mortgage Crisis

Which theory can quantitatively explain the rise in mortgage defaults during the U.S. mortgage crisis? This paper finds that the double‐trigger hypothesis, which attributes mortgage default to the joint occurrence of negative equity and a life event such as unemployment, is consistent with the evidence. By contrast, a traditional frictionless default model strongly overpredicts the increase in default rates. This paper provides microfoundations for double‐trigger behavior in a model where unemployment causes liquidity problems for the borrower. This framework implies that mortgage crises may be mitigated at a lower cost by bailing out borrowers instead of lenders.     

The Hazard Rates of First and Second Defaults

This article examines hazards of repeated mortgage default, conditional on reinstating out of an initial default episode. Results indicate that subsequent default risk for reinstated borrowers is significantly greater than the risk of first default, especially during the first two years after a default episode. In addition, economic factors helpful in predicting first defaults are not helpful in predicting subsequent default episodes. This has important implications for mortgage investors and servicers as industry foreclosure avoidance efforts intensify.     

The inefficiency of refinancing: Why prepayment penalties are good for risky borrowers

This paper provides a theoretical analysis of the efficiency of prepayment penalties in a dynamic competitive lending model with risky borrowers and costly default. When considering improvements in the borrower's creditworthiness as one of the reasons for refinancing mortgages, we show that refinancing penalties can be welfare improving and that they can be particularly beneficial to riskier borrowers in the form of lower mortgage rates, reduced defaults, and increased availability of credit. Thus, a high concentration of prepayment penalties among the riskiest borrowers can be an outcome of efficient equilibrium in a mortgage market. We also provide empirical evidence that is consistent with the key predictions of our model.     

Appraisal Quality and Residential Mortgage Default: Evidence from Alaska

We empirically examine the effect of appraisal quality on subsequent mortgage loan performance using data from the high volatility housing market of Alaska in the 1980s. We develop measures of appraisal quality by computing the residual between a hedonic estimate of house value using available information from other appraisals compared to actual ex ante appraised value. We then estimate proportional hazard models of mortgage default and find that several measures of appraisal quality, particularly appraised value in excess of hedonic estimates, are significantly related to default risk. Using valuations subsequent to loan default, we are also able to evaluate how well house price indices perform in terms of estimating current loan-to-value and offer some additional evidence on the controversy over the role of net equity versus trigger events as determinants of mortgage default. We also show that defaults are related to ex ante measures of housing market conditions, with additional implications for underwriting policies and the current industry trend away from traditional appraisal and toward automated valuation.     

个人抵押贷款违约的相关性因素——基于Copula模型的研究

运用国内商业银行积累的大量数据,统计得到银行个人客户住房抵押贷款多年度、不同信用等级、不同身份特征、分行业和分地区的违约情况,进行非线性的拟合分析,并采用Copula函数度量个人客户违约之间的相关性及厚尾特征。研究表明,房屋价格、客户性别以及受教育程度等与违约概率相关性比较低,在考察的样本区间内,这些因素不显著导致违约发生。另外,信用等级、收入结构和抵押担保剩余额度是影响个人违约决策的重要变量。所采用的模型在个人住房抵押贷款定价与风险管理中获得较好效果,银行可以根据违约状况的变动制定动态利率,随时准备弥补损失。