The Effect of Mortgage Price and Default Risk on Mortgage Spreads

Variations over time in mortgage yield spreads should reflect changes in the underlying prepayment option value; moreover, the relationship between mortgage yield spreads and interest rate dynamics should weaken as the value of the borrowers prepayment option declines. We verify this hypothesis through an empirical analysis of residential mortgage yield spread behavior, and we also present evidence that the strength of the relationship between mortgage spreads and interest rate dynamics weakens (strengthens) as the level of default risk increases (decreases). This result is consistent with the competing risks effect between a borrowers option to prepay or default. Our results demonstrate the importance of accounting for mortgage price discount to par as well as default risk when developing time series of mortgage yields.     

Interest-only and principal-only mortgage strips as interest-rate contingent claims

Interest-only (IO) and principal-only (PO) mortgage strips are valued in a stochastic interest-rate environment. The prepayment rate of the underlying mortgages is affected by two considerations not present in the pure financially rational model: (1) The property owner's holding period is assumed to follow a Gamma distribution, resulting in the possibility of prepayment due to the sale of the property (i.e., prepayment that is too early based on market interest rates); and (2) borrowers are assumed to face heterogeneous transaction costs related to refinancing the existing mortgage, and delay refinancing when market conditions make it optimal to do so (refinancing too late). Properties of IO/PO strips are identified by the finite difference method.     

Subprime Borrowers: Mortgage Transitions and Outcomes

Public policy concerns increasingly have focused on subprime lending. Our research uses a survey of prime and subprime borrowers to address whether borrowers inappropriately are channeled to the subprime segment, if once having taken out a subprime mortgage borrowers are stuck in this market segment, and whether borrowers face higher costs by taking out subprime mortgages. We find that subprime borrowers are less knowledgeable about the mortgage process, are less likely to search for the best mortgage rates, and are less likely to be offered a choice among alternative mortgage terms and instruments—possibly making them more vulnerable to unfavorable mortgage outcomes. Our analysis of market segmentation confirms that typical mortgage underwriting criteria are most important in explaining whether borrowers obtain prime or subprime mortgages—higher credit risk borrowers are more likely to get a subprime loan. Our results further show that search behavior and other demographic factors including adverse life events, age, and Hispanic ethnicity contribute to explaining market segment, suggesting that borrowers may inappropriately receive subprime mortgages. While we find some persistence to market segment—borrowers are more likely to take out a subprime mortgage if their previous mortgage came from the subprime segment—we also find that market segment is not immutable. Analysis of the survey responses indicates that borrowers with subprime mortgages significantly are more dissatisfied with their mortgage outcomes. This is not surprising because subprime borrowers look worse across typical mortgage underwriting criteria. Consistent with policy concerns, however, despite holding constant these and other factors, taking out a mortgage in the subprime segment, by itself, appears to increase dissatisfaction with mortgage outcomes. We do not provide a definitive answer to the question of whether subprime lending, on balance, serves homebuyers well by providing access to mortgage credit to those otherwise constrained, or rather serves homebuyers poorly by inappropriately assigning them to a market where costs are high and the ability to transition to more attractive prime mortgages remains low. Our analysis, however, does provide some empirical support for concerns raised by critics of subprime lending, and for this reason justifies continued public policy debate and analysis.     

The “Rent-To-Own” mortgage and prepayment risk

The most important risk factor in the mortgage and mortgage-backed security market has been prepayment risk. Various innovations have arisen to deal with it but none hedge it fully. The Rent-To-Own (RTO) mortgage discussed here is a mortgage instrument that reduces or even reverses prepayment risk. It does so by creating an incentive structure within the framework of the mortgage contract that penalizes prepayment when interest rates are low and rewards it when interest rates are high. This is the opposite of standard mortgages. The RTO incentive structure is based on a unique buyout feature. Borrowers who want to buy out the financial interest of the lender may do so whenever they want, but the buyout price is a negative function of the market interest rates prevailing currently, that is, at the time of the buyout. Hence the lower these rates, the higher the buyout price. Other advantages of the RTO mortgage are also described.     

GSEs,Mortgage Rates,and the Long-Run Effects of Mortgage Securitization

Our paper compares mortgage securitization undertaken by government-sponsored enterprises (GSEs) with that undertaken by private firms, with an emphasis on how each type of mortgage securitization affects mortgage rates. We build a model illustrating that market structure, government sponsorship, and the characteristics of the mortgages securitized are all important determinants of mortgage rates. We find that GSEs generally—but not always—lower mortgage rates, particularly when the GSEs behave competitively, because the GSEs implicit government backing allows them to sell securities without the credit enhancements needed in the private sector. Using our simulation model, we demonstrate that when mortgages eligible for purchase by the GSEs have characteristics similar to other mortgages, the GSEs implicit government-backing generates differences in mortgage rates similar to those currently observed in the mortgage market (which range between zero and fifty basis points). However, if the mortgages purchased by GSEs are less costly to originate and securitize, and if the GSEs behave competitively, then the simulated spread in mortgage rates can be much larger than that observed in the data.     

The pricing of FIREARMs (“Falling Interest Rate Adjustable-Rate Mortgages”)

The purpose of this article is to propose and price a new type of adjustable-rate mortgage: the FIREARM (Falling Interest Rate Adjustable-Rate Mortgage). The interest payments on this mortgage adjust downward whenever interest rates decline, while remaining stable when interest rates increase. The FIREARM is alternatively priced as a prepayable and non-prepayable mortgage with a spread over the short-term interest rate. We price these two instruments and contrast their prices with those of fixed-rate mortgages using the parsimonious assumptions of a non-stationary arbitrage-free binomial term structure model.     

Commercial Mortgage Default: A Comparison of Logit with Radial Basis Function Networks

This article explores the use of artificial neural networks in the modeling of foreclosure of commercial mortgages. The study employs a large set of individual loan histories previously used in the literature of proportional hazard models on loan default. Radial basis function networks are trained (estimated) using the same input variables as those used in the logistic. The objective is to demonstrate the use of networks in forecasting mortgage default and to compare their performance with that of the logistic benchmark in terms of prediction accuracy. Neural networks are shown to be superior to the logistic in terms of discriminating between good and bad loans. The study performs sensitivity analysis on the average loan and offers suggestions on further improving prediction of defaulting loans.     

Benefits to Homeowners from Mortgage Portfolios Retained by Fannie Mae and Freddie Mac

Mortgage investing is the domain of financial intermediaries, such as Fannie Mae and Freddie Mac, who possess specialized knowledge and experienced analytic teams. Capital is channeled to homeowner/borrowers at lower cost through such entities. As the demand for mortgage borrowing outstrips aggregate domestic saving (which is currently negative) foreign sources of capital should become even more significant. Foreign capital can be channeled efficiently into the U.S. mortgage market by Fannie and Freddie. Their debt has the highest credit standing and their risk management ability has been demonstrated by their enormous retained portfolios of mortgages.     

Mortgage Default: Classification Trees Analysis

We apply the powerful, flexible, and computationally efficient nonparametric Classification and Regression Trees (CART) algorithm to analyze real estate mortgage data. CART is particularly appropriate for our data set because of its strengths in dealing with large data sets, high dimensionality, mixed data types, missing data, different relationships between variables in different parts of the measurement space, and outliers. Moreover, CART is intuitive and easy to interpret and implement. We discuss the pros and cons of CART in relation to traditional methods such as linear logistic regression, nonparametric additive logistic regression, discriminant analysis, partial least squares classification, and neural networks, with particular emphasis on real estate. We use CART to produce the first academic study of Israeli mortgage default data. We find that borrowers features, rather than mortgage contract features, are the strongest predictors of default if accepting icbadli borrowers is more costly than rejecting good ones. If the costs are equal, mortgage features are used as well. The higher (lower) the ratio of misclassification costs of bad risks versus good ones, the lower (higher) are the resulting misclassification rates of bad risks and the higher (lower) are the misclassification rates of good ones. This is consistent with real-world rejection of good risks in an attempt to avoid bad ones.     

Time series models of mortgage choice: Evidence of lender influence

Unit root, co-integration, and Granger Causality are used to test specification of a generalized time series model of mortgage choice. Unit root tests determine that both the fixed-adjustable spread (FAsp) and the proportion of ARM originations (AP) are first difference stationary. The cointegrating vector between FAsp and AP was found to be weak, raising questions regarding their long-term relationship. Causality tests determined that ARM originations Granger causes the fixed-adjustable mortgage spread (APFAsp) rather than FAspAP. This result suggests that mortgage originators adjust the current FAsp spread based on last periods allocation. The coefficient vector for this specification was unstable and became increasingly negative during the 1980s.     

Credit Counseling and Mortgage Termination by Low-Income Households

Published research on credit counseling and mortgage termination is surprisingly scarce, despite substantial growth in this industry. While the purpose of counseling is to assist low-income borrowers to improve their handling of debt and thereby reduce default, counseling may also improve the borrowers understanding of their financial position and thus induce optimal mortgage termination. Using a competing-risks framework, we study the effects on default and prepayment of a counseling program implemented in several Midwest states. We find weak evidence of that the default hazard was lower for graduates of the counseling program, but that their default behavior was more optimal. The prepayment hazard was higher for counseled borrowers, but their prepayment behavior was not more optimal. Overall, counseling seems to affect the lenders profits, but the net effect should be evaluated both in terms of prepayment and default.     

Explicit tests of contingent claims models of mortgage default

This paper provides explicit and powerful tests of contingent claims approaches to modeling mortgage default. We investigate a model of frictionless default (i.e., one in which transactions costs, reputation costs, and moving costs play no role) and analyze its implications-the relationship between equity and default, the timing of default, its dependence upon initial conditions, and the severity of losses. Absent transactions costs and other market imperfections, economic theory makes well-defined predictions about these various outcomes.The empirical analysis is based upon two particularly rich bodies of micro data: one indicating the default and loss experience of all mortgages purchased by the Federal Home Mortgage Corporation (Freddie Mac), and a large sample of all repeat sales of single family houses whose mortgages were purchased by Freddie Mac since 1976.     

On the Economics of Subprime Lending

US mortgage markets have evolved radically in recent years. An important part of the change has been the rise of the subprime market, characterized by loans with high default rates, dominance by specialized subprime lenders rather than full-service lenders, and little coverage by the secondary mortgage market. In this paper, we examine these and other stylized facts with standard tools used by financial economists to describe market structure in other contexts. We use three models to examine market structure: an option-based approach to mortgage pricing in which we argue that subprime options are different from prime options, causing different contracts and prices; and two models based on asymmetric information–one with asymmetry between borrowers and lenders, and one with the asymmetry between lenders and the secondary market. In both of the asymmetric-information models, investors set up incentives for borrowers or loan sellers to reveal information, primarily through costs of rejection.     

Do mortgage rates vary based on household default characteristics? Evidence on rate sorting and credit rationing

Credit screening models suggest that lenders vary loan rates and debt ceilings across applicants on the basis of credit risk. We argue that regulatory constraints such as Fair Lending Laws may preclude rate sorting while increasing lender use of debt ceilings to adjust for applicant credit risk. Using household data from the 1983 SCF, we find that mortgage rates do not vary with applicant credit risk whereas related studies find that debt ceilings vary with borrower risk attributes. Together, these findings support arguments that regulatory constraints reduce rate sorting while increasing the use of non-price terms in the mortgage contract.     

The Relationships Between Mortgage Rates and Capital-Market Rates Under Alternative Market Conditions

Mortgage interest rates have become more integrated with other capital-market interest rates over recent decades, apparently as a result of the deregulation of financial markets. The link is both imperfect and time-varying. Mortgage rates during some time periods appear to be sticky with respect to their adjustment to changes in capital-market rates. We examine the relationship between weekly conventional mortgage rates and the interest rates on treasury and corporate securities under differing market conditions. We draw three conclusions based on the analysis. First, deregulation changed the link between mortgage rates and riskless interest rates, which confirms the findings of Goebel and Ma (1993). Second, mortgage rates were cointegrated with risky interest rates even before deregulation. Third, the link between mortgage rates and the risky bond rate can be associated with the behavior of the risk premium in the bond rate. The observed relationship is consistent with the stickiness observed by Haney (1988) and causes a more pronounced stickiness when rates are falling than when they are rising.     

A General Theorem on the Comparative Statics of Changes in Risk

In this paper, the concept of absolutely riskier than is introduced to generalize Gollier's (Journal of Economic Theory, 66, 522–535) necessary and sufficient conditions for the comparative statics of a change in risk for risk averters. The restrictive assumption that the payoff function is monotonic in the risk is relaxed. The policymaker's choice problem, the newsboy problem, and a farmer's example are used to illustrate how easily the monotonicity assumption is violated. Finally, some important properties of the concept of absolutely riskier than, such as its relation with the concept of second-order stochastic dominance, are illustrated using the farmer's example.     

Performance of residential mortgages in low and moderate-income neighborhoods

This paper presents the first data on performance of mortgages on residences located in lowand moderate-income neighborhoods of U.S. cities. It provides new data on delinquencies and foreclosure provided by a sample of lenders who are members of the National Association of Affordable Housing Lenders and who have lending programs established pursuant to the Community Reinvestment Act.Sample mortgages on multifamily dwellings perform comparably with national sample data, whereas sample mortgages on single-family mortgages perform much better than comparable national sample data.The findings of this paper demonstrate clearly that lending programs in lowand moderate-income neighborhoods can be viable. The findings do not, however, help to settle the issue as the racial or gender discrimination in mortgage origination.This paper is based on Performance Analysis of Community Reinvestment Programs, prepared by the athors for the Woodstock Institute, Chicago, IL.     

Bank lending ‘manias’ in theory and history

A popular view of banking crises sees them as consequences of prior bank lending manias. Such manias are supposed to be especially likely in legally unrestricted banking systems, where banks can issue notes and are not subject to statutory reserve requirements. Here it is argued that the bank lending mania hypothesis (1) exaggerates the role of subjective factors, including bankers' confidence or optimism, as a stimulus to bank lending, and (2) is not supported by evidence from past, legally unrestricted banking systems.     

Cointegration and causal relations in mortgage and capital markets

In years past, credit rationing resulted in the primary mortgage market being segmented from national capital markets. Some research suggests that the deregulation of depository institutions in the early 1980s along with the exponential growth in the secondary mortgage market, has resulted in a primary mortgage market more fully integrated with national capital markets. This study employs Granger Causality to test primary and secondary mortgage market segmentation. Our findings support the conclusion that causality is unidirectional from the treasury market to the primary and secondary mortgage market. The results also indicate that mortgage market speed of adjustment increased significantly by the end of the decade.     

Optimal Loan Interest Rate Contract Design

This paper analyzes optimal loan interest rate contracts under conditions of risky, symmetric information for one-period (static) and multi-period (dynamic) models. The optimal loan interest rate depends upon the volatility of, and co-variation among the market interest rate, borrower collateral, and borrower income, as well as the time horizon and the risk preferences of lenders and borrowers. For a risk-averse borrower with stochastic collateral, variable interest rate contracts are, in general, Pareto optimal. For plausible assumptions, the optimal loan interest rate for the multi-period model often exhibits muted responses to changes in market interest rates, making fixed rate loans a reasonable approximation for the optimal loan. Hence, in the absence of optimal contracts, long-term (short-term) borrowers tend to prefer fixed rate (variable) contracts.