The good,the bad and the impaired: A credit risk model of the Irish mortgage market

Using a uniquely constructed loan-level dataset of the residential mortgage book of Irish financial institutions, this paper provides a framework for estimating default probabilities of individual mortgages. In contrast to the popular stock delinquency approach, this model provides estimates of default and cure flows: a requirement of the stress test approach adopted by the European Central Bank's comprehensive assessment. In addition, both default and cure transitions are modelled as functions of micro- and macro-covariates including loan characteristics and current macroeconomic conditions such as house prices and unemployment. When comparing the competing equity and affordability effects, labour market deterioration played a stronger role than house equity in the rise of Irish default rates. For cures, a scarring effect of default is identified and estimated with the probability of a loan returning to performing reducing by almost four per cent each month a loan remains delinquent.     

Mortgage defaults

A life-cycle model is developed in which households face income and house-price risk and buy houses with mortgages. This model, which accounts for key features in U.S. data, is used as a laboratory for prudential policy. Recourse mortgages increase the cost of default but also lower equity and increase payments. The effect on default is nonmonotonic. Loan-to-value (LTV) limits increase equity and lower the default rate, with negligible effects on housing demand. Combining recourse mortgages and LTV limits reduces the default rate while boosting housing demand. Together, they also prevent spikes in default after large declines in aggregate house prices.     

Loss given default of high loan-to-value residential mortgages

This paper studies loss given default using a large set of historical loan-level default and recovery data of high loan-to-value residential mortgages from several private mortgage insurance companies. We show that loss given default can largely be explained by various characteristics associated with the loan, the underlying property, and the default, foreclosure, and settlement process. We find that the current loan-to-value ratio is the single most important determinant. More importantly, mortgage loss severity in distressed housing markets is significantly higher than under normal housing market conditions. These findings have important policy implications for several key issues in Basel II implementation.     

Credit History and the Performance of Prime and Nonprime Mortgages

Although nonprime lending has experienced steady or even explosive growth over the last decade very little is known about the performance characteristics of these mortgages. Using data from national secondary market institutions, this paper estimates a competing risks proportional hazard model, which includes unobserved heterogeneity. The analysis examines the performance of 30-year fixed rate owner occupied home purchase mortgages from February 1995 to the end of 1999 and compares nonprime and prime loan default and prepayment behavior. Nonprime loans are identified by mortgage interest rates that are substantially higher than the prevailing prime rate. Results indicate that nonprime mortgages differ significantly from prime mortgages: they have different risk characteristics at origination; they default at elevated levels; and they respond differently to the incentives to prepay and default. For instance, nonprime mortgages are less responsive to how much the option to call the mortgage or refinance is in the money and this effect is magnified for mortgages with low credit scores. Tests also reveal that default rates are less responsive to homeowner equity when credit scores are included in the specification.     

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.     

Housing,mortgage bailout guarantees and the macro economy

What are the macroeconomic and distributional effects of government bailout guarantees for Government Sponsored Enterprises (e.g., Fannie Mae)? A model with heterogeneous, infinitely lived households and competitive housing and mortgage markets is constructed to evaluate this question. Households can default on their mortgages via foreclosure. The bailout guarantee is a tax-financed mortgage interest rate subsidy. Eliminating this subsidy leads to a large decline in mortgage origination and increases aggregate welfare by 0.5% in consumption equivalent variation, but has little effect on foreclosure rates and housing investment. The interest rate subsidy is a regressive policy: it hurts low-income and low-asset households.     

Valuation of Residential Mortgage-Backed Securities with Default Risk Using an Intensity-Based Approach

This paper develops a valuation model for fixed-rate mortgages, mortgage pools, and residential mortgage-backed securities (RMBS's) using an intensity-based approach. This model incorporates full prepayment, partial prepayment, and default in valuing a mortgage. Full prepayment is further classified into “refinancing” and “sale of a house” depending on the reason. The time of occurrence of each of these three types of prepayment and default is modeled as the first jump time of a Cox process. Under these conditions, the valuation formula for a mortgage as well as a partial differential equation (PDE) that the mortgage value satisfies is provided. As for implementation of the model, the short-term riskless interest rate and the house price are adopted as state variables. Each intensity process is specified in a manner that allows a jump in intensity depending on the state variables and the borrower's incentive for prepayment or default. Through such specifications, it is shown that our model has characteristics similar to some structural models in previous literature. As for the numerical method for valuation, we propose a simple backward induction technique on a tree instead of the commonly used Monte Carlo method. Additionally, the method for estimating the model is discussed, and the results of numerical simulations are reported.This paper represents the view of the author and does note necessarily the views of the Mitsubishi UFJ Securities Co., Ltd. or members of its staff.     

The closing rate on residential mortgage commitments: An econometric analysis

Mortgage lenders routinely guarantee rates and points for periods of 60 days or more and hedge the inherent interest rate risk by selling the proportion of mortgages expected to close in forward markets. This article presents a model of the decision to close on the mortgage and demonstrates that the estimates of the model increase the precision of closing rate forecasts. The analysis indicates that changes in mortgage rates are important determinants of the closing rate for fixed-rate mortgages (FRM) and adjustable-rate mortgages (ARM). Other important factors include whether the mortgage is for a new purchase, for owner occupancy, and for a single-family house, and what the overall level of mortgage rates and the loan-to-value ratio are and whether the rate guarantee was granted at the application date or later.     

Valuing mortgage loan servicing

We develop an intertemporal model for valuing mortgage loan servicing contracts. The model includes a stochastic short-term interest rate and realized inflation rate which jointly determine the current mortgage coupon rate, the mortgagor's prepayment decision, the servicer's future net cash flows, and the rate at which to discount these future cash flows. Several potential uses of the model for institutions that service mortgages and trade servicing portfolios are illustrated by the application of the model to servicing fixed-rate mortgages and adjustable-rate mortgages. The model also is applicable to regulatory issues and to the servicing of other types of loans.The authors gratefully acknowledge support from the Federal Home Loan Bank Board, Washington, D.C., the Purdue Research Foundation, West Lafayette, Indiana, and the Richard D. Irwin Foundation, Homewood, Illinois.     

Breakeven Determination of Loan Limits for Reverse Mortgages under Information Asymmetry

Since the loan limit of a reverse mortgage is a major concern for the borrower as well as the lender, this paper attempts to develop an option-based model to evaluate the loan limits of reverse mortgages. Our model can identify several crucial determinants for reverse mortgage loan limits, such as initial housing price, expected housing price growth, house price volatility, mortality distribution, and interest rates. We also pay special attention to the important implication of mortgage lenders’ informational advantage over reverse mortgage borrowers concerning housing market risk. In reverse mortgage markets, the elderly borrowers typically hold far less, relative to the lenders, or no information about the lenders’ underlying mortgage pools. Such information asymmetry leads these two categories of market participants to generate different perspectives on the risk of the collateralized properties, which can be identified to be important in determining the maximum loan amounts of reverse mortgages. We further find that the maximum loan amount of a reverse mortgage decreases in the correlation between the returns on the pooled underlying housing properties but increases with the number of the pooled mortgages.     

Subprime Loan Default Resolutions: Do They Vary Across Mortgage Products and Borrower Demographic Groups?

This paper examines default outcomes for subprime first lien loans during the recent subprime mortgage boom. It conducts this investigation in two phases. The paper first examines factors associated with pre-foreclosure outcomes for subprime mortgages in default. It then examines factors associated with different outcomes for loans that enter foreclosure. These factors include less understood elements such as mortgage product features and borrower demographics. The analysis is based on detailed loan-level data and employs multinomial logit models in a hazard framework. Results show that default resolutions vary with product features and borrower demographics. Adjustable rate and interest-only mortgages, and loans with low- or no-documentation are more likely to enter foreclosure proceedings, and, once in foreclosure, are more likely to become REO. The existence of junior liens increases the probability of the loan remaining in default. Owner-occupancy is associated with lower likelihood of foreclosure initiation and REO, and greater likelihood of curing default. Additionally, default outcomes are impacted by local legal, economic and housing market conditions, and the equity in the home.     

Mortgage risks,debt literacy and financial advice

A limited understanding of mortgage contracts and the risks involved may have contributed to the outbreak of the 2007–2008 financial crisis. We developed a special questionnaire relating mortgage loan decisions to financial knowledge and financial advice. Our results demonstrate that homeowners appear to be well aware of mortgage risks. Large loans relative to home value are perceived as riskier, as are loans with large mortgage payments relative to income and loans linked to investment vehicles. Homeowners with riskier mortgages indicated that they could encounter financial problems should house prices or their income decline. Homeowners with relatively low debt literacy are more likely to take out traditional mortgages with principal repayments over the maturity of the loan. Riskier mortgages are more prevalent among homeowners with a better understanding of loan contracts. Financially less sophisticated homeowners consulting mortgage brokers, too, hold riskier mortgages.     

A model of mortgage losses and its applications for macroprudential instruments

We develop a theoretical model of mortgage loss rates that evaluates their main underlying risk factors. Following the model, loss rates are positively influenced by the house price level, the loan-to-value of mortgages, interest rates, and the unemployment rate. They are negatively influenced by the growth of house prices and the income level. The calibration of the model for the US and Switzerland demonstrates that it is able to describe the overall development of actual mortgage loss rates. In addition, we show potential applications of the model for different macroprudential instruments: stress tests, countercyclical buffer, and setting risk weights for mortgages with different loan-to-value and loan-to-income ratios.     

An empirical analysis of home equity loan and line performance

Given the growth in home equity lending during the 1990s, it is imperative that lenders and regulators understand the risks associated with this segment of the residential mortgage market. Using a unique panel data set of over 135,000 homeowners with second mortgages, our analysis indicates that significant differences exist in the prepayment and default probabilities of home equity loans and lines, providing insights into bank minimum capital requirements. We find that households with equity loans are relatively more sensitive to changes in interest rates. By contrast, households with equity lines are more sensitive to appreciation in property value.     

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.     

First Mortgages,Second Mortgages,and Their Default

Using 35,437 pairs of first and second mortgages matched from within a much larger set of subprime mortgages, this paper tracks and describes the tendency for either one of the mortgages to enter default, as well as the tendency for either the one or the other mortgage to ever return to being current, all this in a possibly repeated manner. Thus, the entire, interconnected default history of pairs of first and second mortgages is explored, as well as compared to theoretical predictions.     

Mortgage Loan Securitization and Relative Loan Performance

We compare the ex ante observable risk characteristics, the default performance, and the pricing of securitized mortgage loans to mortgage loans retained by the original lender. In our sample of loans originated between 2000 and 2007, we find that privately securitized fixed and adjustable-rate mortgages were riskier ex ante than lender-retained loans or loans securitized through the government sponsored agencies. We do not find any evidence of differential loan performance for privately securitized fixed-rate mortgages. We find evidence that privately securitized adjustable-rate mortgages performed worse than retained mortgages, although other observable factors appear to be more economically important determinants of mortgage default. We do not find any evidence of a compensating premium in the loan rates for privately securitized adjustable-rate mortgages.     

Originators,wholesalers, and conduits: The marginal value of the contract rate on 30-year conventional mortgages

The model we present solves for the value of an incremental change in the mortgage contract given an expectation about the time the mortgage will be outstanding and a required return for this time span. The marginal value participants in the primary mortgage market place on the contract rate of a 30-year conventional mortgage determines the array of bids for new mortgage production. Mortgagors can issue mortgages at various discounts. High discounts are associated with low contract rates, and low discounts are associated with high contract rates. This article examines the way wholesale dealers and conduits value the various contract rates associated with current production of 30-year conventional mortgages.     

The Determinants of Attitudes toward Strategic Default on Mortgages

We use survey data to measure households’ propensity to default on mortgages even if they can afford to pay them (strategic default) when the value of the mortgage exceeds the value of the house. The willingness to default increases in both the absolute and the relative size of the home‐equity shortfall. Our evidence suggests that this willingness is affected by both pecuniary and non‐pecuniary factors, such as views about fairness and morality. We also find that exposure to other people who strategically defaulted increases the propensity to default strategically because it conveys information about the probability of being sued.     

Characteristics of Mortgage Terminations: an Analysis of a Loan-Level Dataset

Understanding mortgage termination behavior is crucial for valuating mortgage-backed securities. Analyzing a unique loan-level dataset, this study examines the characteristics of mortgage prepayment and default behaviors in the Korean housing and housing finance markets. We also analyze mortgage termination behaviors across regions, loan purposes, and periods. The results suggest that the prepayment rate of fixed-rate mortgages (FRMs) and the ratio of adjustable-rate mortgages to FRMs can provide meaningful signals for the Korean household economy. Although the macro-prudential policies pertaining to the loan-to-value ratio (LTV) and debt-to-income ratio (DTI) are very effective, their effects can vary depending on the region or loan purpose. Furthermore, the DTI and credit score cannot always identify the default risks of mortgages not intended for housing purchases even though such mortgages are more vulnerable to macroeconomic changes. The observed changes in default behavior indicate that the government’s policies to promote fixed-rate loans have achieved a certain degree of success.