Negative default dependence in supplier networks

The financial defaults of suppliers in a supplier network are significant risks and causes of uncertainty for buying firms. Hitherto, it has been largely neglected that default probabilities of suppliers in supplier networks are not independent of each other. We aim to overcome this shortcoming by studying negative supplier default dependencies: situations where a surviving supplier may benefit from the default of another supplier, resulting in a lower default probability. We use empirical data from the automotive supplier industry and copula functions, a method of representing joint distribution functions with particular marginals, to capture the default dependency between automotive suppliers and simulate various scenarios with negative default dependency. We also conduct a comparative static analysis illustrating the significant impact of negative default dependence. Our findings should spur managers to analyze their supplier networks with respect to default dependencies, and to take this phenomenon into consideration when making sourcing decisions.     

An Empirical Test of a Two‐Factor Mortgage Valuation Model: How Much Do House Prices Matter?

This article develops a two-factor structural mortgage pricing model in which rational mortgage-holders choose when to prepay and default in response to changes in both interest rates and house prices. We estimate the model using comprehensive data on the pool-level termination rates for Freddie Mac Participation Certificates issued between 1991 and 2002. The model exhibits a statistically and economically significant improvement over the nested one-factor (interest-rate only) model in its ability to match historical prepayment data. Moreover, the two-factor model produces origination prices that are significantly closer to those quoted in the to-be-announced market than the one-factor model. Our results have important implications for hedging mortgage-backed securities.     

Some Loans Are More Equal than Others: Third–Party Originations and Defaults in the Subprime Mortgage Industry

We show how agency problems between lenders (principals) and third–party originators (TPO; agents) imply that TPO–originated loans are more likely to default than similar retail–originated loans. The nature of the agency problem is that TPOs are compensated for writing loans, but are not completely held accountable for the subsequent performance of those loans. Using a hazard model with jointly estimated competing risks and unobserved heterogeneity, we find empirical support for the TPO/default prediction using individual fixed–rate subprime loans with first liens secured by residential real estate originated between January 1, 1996, and December 31, 1998. We find that apparently equal loans (similar ability to pay, option incentives and term) can have unequal default probabilities. We also find that, initially, the agency–cost risk was not priced. At first, the market did not recognize the higher channel risk, since TPO and retail loans received similar interest rates even though the TPO loans were more likely to default. We also show that this inefficiency was short–lived. As the difference in default rates became apparent, interest rates on TPO loans rose about 50 basis points above otherwise similar retail loans.     

Modeling the Conditional Probability of Foreclosure in the Context of Single-Family Mortgage Default Resolutions

Both empirical and pricing-simulation models of mortgage default focus on foreclosure in a one-step decision framework. Such models are misspecified to the extent that mortgage default and foreclosure are two separate decisions or events, where foreclosure is but one outcome of a default episode. This study examines the dynamics of mortgage borrower default episodes using a large sample of FHA-insured single-family mortgages. We estimate the influence of borrower characteristics, mortgage terms, and economic conditions on probabilities of various resolutions, highlighting under what conditions foreclosure is more likely to result from mortgage default.     

The Impact of Second Loans on Subprime Mortgage Defaults

An estimated 12.6% of primary mortgage loans were simultaneously originated with a second loan from 2004 until 2008, although relatively little is known about how the presence of such subordinate loans affects the default decisions of borrowers. We use a novel data series of loan servicing records from 2002 until 2010 to identify such borrowers and find evidence that the default behavior of these borrowers significantly differs from borrowers without second loans. Estimating a discrete‐time proportional odds hazard model, we find borrowers with a second loan were 62.7% more likely to default each month on their primary loan when conditioning alone on the attributes of the primary loan. However, borrowers of second loans were 58.3% less likely to default on their primary loan as compared to single‐loan borrowers with equivalent current combined attributes (i.e., loan‐to‐value, balance and interest rate). We hypothesize and provide empirical evidence that this occurs because borrowers with second loans have the option to sequentially default on each loan since subordinate lenders will not pursue foreclosure if borrowers have insufficient equity. Lenders of defaulted subordinate debt may revisit their decision to foreclose in the future after housing markets start to recover, thus prompting a new round of foreclosures.     

Commercial Mortgage Pricing with Unobservable Borrower Default Costs

This paper develops a pricing model for commercial real estate mortgage debt that recognizes the influence of default transaction costs on the borrower's default decision. These costs are heterogeneous across borrowers and largely un-observable to the lender/investor at the time of origination or loan purchase. A recognition of these unobservable costs can explain why borrower default decisions may differ from those predicted by "ruthless" mortgage-default pricing models. We address the determinants of default choice and timing by replacing sharp default boundaries found in the ruthless models with "fuzzy" boundaries that account for investor uncertainty with respect to evaluating borrower default decisions. To implement our model, we estimate probabilities of default as a junction of time and net equity in the property. Then, given that default occurs, loss severities are modeled based on expected property value recovery net of foreclosure costs and time until the asset is actually sold. Under reasonable parameter value choices, resulting Monte Carlo simulations produce numerical mortgage price estimates as well as component default frequency and severity levels that realistically reflect default premiums and loss levels observed in the marketplace.     

浅析利率调整对住房抵押贷款违约风险的影响

住房贷款利率的变化对房地产价格产生着巨大影响,房地产价格又是住房抵押贷款中重要因素,与住房抵押贷款风险密切相关。违约风险是住房低押贷款风险中最基本最主要的风险,也称信用风险。论文将从理论上分析利率政策调整对住宅抵押贷款违约风险的影响,并提出相应的防范措施。     

A Lattice Approach to Pricing Fixed-Rate Mortgages with Default and Prepayment Options

Existing models on the pricing of default and prepayment options in fixed-rate mortgages either use numerical methds or they do not consider refinancing or other transaction costs involved in default and prepayment. We provide in this paper an application of the Boyle [1] lattice model to price secured debt with two risky assets. This model is simple, efficient and capable of considering the major types of transaction costs involved in prepayment and default. Using our model, we estimate the option values under a range of assumptions about the underlying parameters. We also provide some comparisons of the lattice model estimates to other models in the literature.     

The Effect of Mortgage Payment Reduction on Default: Evidence from the Home Affordable Refinance Program

This article evaluates the effect of payment reduction on mortgage default within the context of the Home Affordable Refinance Program. We find that mortgage default is sensitive to payment reduction using univariate, duration and hazard modeling approaches. A relative risk Cox model of default with time‐varying covariates estimates that a 10% reduction in mortgage payment is associated with about a 10–11% reduction in monthly default hazard for loans. This finding is robust to the inclusion of empirically important mortgage risk drivers (such as current loan‐to‐value and FICO score) as well as controlling for selection effects based on observables.     

The Role of Home Equity Lending in the Recent Mortgage Crisis

Home equity lending grew rapidly from 2000 to 2008 with balances more than tripling. In this article, we examine the role this phenomenon may have played in increasing aggregate default risk during the mortgage crisis. We also document a relationship between growth in home equity lending and high house price depreciation and first mortgage default during the downturn of 2006–2009. Line of credit growth is shown to be associated with large increases in nonowner‐occupied property purchases, suggesting that home equity lines of credit were tapped to fund such investments, exacerbating default rates during the market downturn.     

Determinants of Multifamily Mortgage Default

Option–based models of mortgage default posit that the central measure of default risk is the loan–to–value (LTV) ratio. We argue, however, that an unrecognized problem with extending the basic option model to existing multifamily and commercial mortgages is that key variables in the option model are endogenous to the loan origination and property sale process. This endogeneity implies, among other things, that no empirical relationship may be observed between default and LTV. Since lenders may require lower LTVs in order to mitigate risk, mortgages with low and moderate LTVs may be as likely to default as those with high LTVs. Mindful of this risk endogeneity and its empirical implications, we examine the default experience of 495 fixed–rate multifamily mortgage loans securitized by the Resolution Trust Corporation (RTC) and the Federal Deposit Insurance Corporation (FDIC) during the period 1991–1996. The extensive nature of the data supports multivariate analysis of default incidence in a number of respects not possible in previous studies. Consistent with our expectations, we find that LTV evidences no relationship to default incidence, while the strongest predictors of default are property characteristics, including three–digit ZIP code location and initial cash flow as reflected in the debt coverage ratio. The latter results are particularly interesting in that they dominated the influence of postorigination changes in the local economy.     

Do Liquidated Damages Clauses Affect Strategic Mortgage Default Morality? A Test of the Disjunctive Thesis

We test the disjunctive thesis as it relates to mortgage contracts and find that a liquidated damages clause shifts ones view of a mortgage from a promise to perform to either a promise to perform or pay compensatory damages. However, when a strategic mortgage default is responsible for the breach, the perceived immorality of this action overwhelms the liquidated damages clause effect in support of the disjunctive thesis. We also find that people's conscious “experimentally stated preference” moral stance on installment loan (mortgages, auto loans, credit card debt and even cell phone contracts) default significantly differs from their subconscious “experimentally revealed preference” moral stance indicating a difference between what people say they believe and what they actually believe.     

Equity and Nonequity Determinants of FHA Single-Family Mortgage Foreclosures in the 1980s

We examine foreclosures on FHA single-family mortgages insured during the 1975–87 period. The importance of the market value of borrower equity and national house price dispersion support much earlier work emphasizing the key role of negative equity in triggering default. The lower is "mean" market-value equity, and the greater is dispersion, the greater is the fraction of borrowers likely to have negative equity. The unemployment rate and the book value of borrower equity are also shown to be significant determinants of default. Unemployment is one of those events that can force borrowers to move. The moving decision increases the likelihood of default because moving costs no longer deter default, and the costs of selling the house reduce the effective equity in the house. The book value of equity is relevant to this decision because it is what the sellers receive if they move without defaulting. Not only are both of these variables significant determinants of default, but the smaller is book equity, the greater is employment impact (with large book equity, unemployment should not matter because selling the house is preferred to default).     

Pricing the default option of international sovereign borrowers

When a country in debt encounters serious difficulties servicing that debt, the option to default begins to look attractive. Yet, barring major political upheavals, default has rarely occurred in the post-war era. The reason is that countries in trouble are able to capture (through renegotiations) some of the value of their option to default. We model this process in a manner which allows us to estimate the value of the default option which lenders issue to sovereign borrowers.We wish to thank our discussant, Malick Ousmane Sy, and the chair of our session, Lester W. Johnson, for their helpful comments.     

The Subprime Virus

We examine the correlation between prime mortgage default risk and the introduction of subprime mortgages in a local area. We motivate our analysis with a model of a default contagion effect that spreads the effect of a mortgage foreclosure from one property to surrounding properties. Through numerical analysis, we demonstrate the effect of subprime mortgage originations to the risk of prime mortgages. Finally, we offer empirical support for our model by examining the spatial variation in MSA prime mortgage default rates and the level of subprime mortgage activity.     

Prepayment Penalty as a Screening Mechanism for Default and Prepayment Risks

The objective of this article is to offer a theoretical model of asymmetric information to analyze the screening role of prepayment penalty. We consider both default risk and prepayment risk. What makes the role of prepayment penalty interesting and more complicated is that a borrower's contract choice could send conflicting signals to the lender about that borrower's default and prepayment risk type. This is different from earlier theoretical models of mortgage choice under asymmetric information where a certain aspect of the contract (e.g., discount points or loan‐to‐value ratio) is explored as a screening mechanism for a single risk dimension (default risk or prepayment risk) of the borrower type. We show the existence of separating equilibria where different default and prepayment risk types choose contracts with different combinations of prepayment penalty and interest rate. For certain parameter combinations, the model also generates a pooling equilibrium where all borrower types obtain the same contract. Our analysis could offer a partial explanation for the observation that contracts with prepayment penalties are a lot less prevalent than contracts with points.     

Income, Location and Default: Some Implications for Community Lending

This paper investigates differences in default losses across income groups and neighborhoods, in an effort to see if there are significant differences between default experience on loans to low-income households or low-income neighborhoods and other loans. We find that while defaults and losses are somewhat higher in low-income neighborhoods, default behavior is similar in the sense that responses to negative equity are similar across neighborhoods, and remaining differences are small and might be explained by omitted variables such as those measuring credit history.     

The Conditional Probability of Mortgage Default

This research examines the implications of contingent-claims models for empirical research on default. We focus on the probability of default over a short horizon given the current state of the world, i.e. , the conditional probability of default, which more closely resembles the estimates of empirical models. We highlight the differences between the conditional and unconditional approaches and provide guidance for empirical research by illuminating situations where the expected sign reverses over the shorter horizon or where the functional form is highly nonlinear.     

Do Riskier Borrowers Borrow More?

Conventional wisdom in the mortgage industry holds that loan-to-value (LTV) ratios are positively correlated with mortgage default rates. However, not all empirical studies of mortgage loan performance support this view. This paper offers a theoretical signaling model of why the correlation between LTV ratios and default risk is contingent upon the default costs of the borrower. Specifically, the model proposes that when default costs are high there exists a separating equilibrium in which risky borrowers will self-select into lower LTV loans to reduce the probability of facing a costly default, while safe borrowers will self-select into higher LTV loans as a signal of their enhanced creditworthiness. This adverse selection process gives rise to the possibility of higher default probabilities for lower LTV loans. Conversely, when default costs are low the conventional result, in which risky borrowers select higher LTV loans than safe borrowers, is obtained. Empirical results, based on a sample of 859 single-family residential mortgage loans drawn from the portfolio of a national mortgage lender, are consistent with the separating equilibria predicted by the model.     

The Conditional Probability of Foreclosure: An Empirical Analysis of Conventional Mortgage Loan Defaults

This paper analyzes the factors affecting the conditional probability that defaulted residential mortgage loans will foreclose. We analyze a large national sample of conventional loans, which have been in default at least once during the 1988 to 1994 period. For such loans, lenders and borrowers either individually or jointly make choices which lead to the following outcomes: (1) resumption of payments, (2) termination by prepayment, or (3) foreclosure. Our estimates of a logit model indicate that termination option values and local area economic and housing market conditions affect default resolution probabilities. Perhaps more importantly, simulations using the logit model indicate that the efficiency of the default resolution process may be substantially improved by legal and regulatory reforms.