• Selected
• Entire List

Abstract:
We develop estimates of risk-based capital requirements for single-family mortgage loans held in portfolio by financial intermediaries. Our method relies on simulation of default and loss probability distributions via simulation of changes in economic variables with conditional default probabilities calibrated to recent actual mortgage loan performance data from the 1990s. Based on simulations with varying input parameters, we find that appropriate capital charges for credit risk vary substantially with loan or borrower characteristics and are generally below the current regulatory standard. These factors may help explain the high degree of securitization, or regulatory capital arbitrage, observed for this asset category.

Capital, mortgage, risk, regulation

Abstract:
The magnitude of the effect of government-sponsored enterprise purchases on primary mortgage market rates has been a difficult research question to answer with differing data and competing methodologies producing different results. In this paper we present a new approach using loan level data and controlling for any credit risk differential between conforming and non-conforming loans. Our method also addresses econometric problems of endogeneity and sample selection bias. We find that conforming loans have yields spread about 2.6% lower (4.5 basis points) on a risk-adjusted basis compared to other loans. This is lower than previous estimates appearing in the literature and may result from the greater precision available in our loan level dataset that allows us to control for credit risk.

Mortgage yield spreads, securitization, government-sponsored enterprise

Abstract:
Banks face the choice of keeping loans on their balance sheet as private debt or transforming them into public debt via asset securitization. Securitization transfers credit and interest rate risk, increases liquidity, augments fee income, and improves capital ratios. Yet many lenders still choose to retain a portion of their loans in portfolio. An open research question is whether lenders exploit asymmetric information to sell riskier loans into the public markets or retain riskier loans in response to regulatory capital incentives (regulatory capital arbitrage). We examine this question empirically using micro-level data and find that securitized mortgage loans have experienced lower ex-post defaults than those retained in portfolio, providing evidence consistent with the latter explanation for securitization.

Banks, debt, securitization, regulatory capital

Abstract:
The cause of the "housing bubble" associated with the sharp rise and then drop in home prices over the period 1998-2008 has been the focus of significant policy and research attention. The dramatic increase in subprime lending during this period has been broadly blamed for these market dynamics. In this paper we empirically investigate the validity of this hypothesis vs. several other alternative explanations. A model of house price dynamics over the period 1998-2006 is specified and estimated using a cross-sectional time-series data base across 20 metropolitan areas over the period 1998-2006. Results suggest that prior to early 2004, economic fundamentals provide the primary explanation for house price dynamics. Subprime credit activity does not seem to have had much impact on subsequent house price returns at any time during the observation period, although there is strong evidence of a price-boosting effect by investor loans. However, we do find strong evidence that a credit regime shift took place in late 2003, as the GSE's were displaced in the market by private issuers of new mortgage products. Market fundamentals became insignificant in affecting house price returns, and the price-momentum conditions characteristic of a "bubble" were created. Thus, rather than causing the run-up in house prices, the subprime market may well have been a joint product, along with house price increases, (i.e., the "tail") of the changing institutional, political, and regulatory environment characteristic of the period after late 2003 (the "dog").

subprime, housing bubble

Abstract:
We extend the work of Ambrose and LaCour-Little (2001) on traditional one-year adjustable rate mortgages by analyzing the performance of 3/27 hybrid instruments. Under this contract innovation, which first appeared in the mid-1990s, note rates are fixed for three years after which they convert to a traditional one-year adjustment schedule. We find high rates of prepayment, particularly at time of initial rate adjustment, and relatively high rates of default, as would be consistent with the payment shock that often affects adjustable rate loans.

adjustable rate mortgage, prepayment, default

Abstract:
The release of the 2004-2005 Home Mortgage Disclosure Act data raised a number of questions given the increase in the number and percentage of higher-priced home mortgage loans and continued differentials across demographic groups. This paper assesses three possible explanations for the observed increase in 2005 over 2004: (1) changes in lender business practices; (2) changes in the risk profile of borrowers; and (3) changes in the yield curve environment. Results suggest that after controlling for the mix of loan types, credit risk factors, and the yield curve, there was no statistically significant increase in reportable volume for loans originated directly by lenders during 2005, though indirect, wholesale originations did significantly increase. The findings also reveal that the market price of risk increased by about 15 basis points in 2005 versus 2004, implying that mortgage costs increased for all borrowers on a risk-adjusted basis.

Home Mortgage Disclosure Act, HMDA, home loan, credit risk, yield curve

Abstract:
The public release of the 2004-2005 Home Mortgage Disclosure Act data raised a number of questions given the increase in the number and percentage of higher-priced home mortgage loans and continued differentials across demographic groups. Here we assess three possible explanations for the observed increase in 2005 over 2004: (1) changes in lender business practices; (2) changes in the risk profile of borrowers; and (3) changes in the yield curve environment. Results suggest that after controlling for the mix of loan types, credit risk factors, and the yield curve, there was no statistically significant increase in reportable volume for loans originated directly by lenders during 2005, though indirect, wholesale originations did significantly increase. Finally, given a model of the factors affecting results for 2004-2005, we predict that 2006 results will continue to show an increase in the percentage of loans that are higher priced when final numbers are released in September 2007.

HMDA, mortgage, subprime

Abstract:
Developing a good prepayment model is a central task in the valuation of mortgages and mortgage-backed securities but conventional parametric models often have bad out-of-sample predictive ability. A likely explanation is the highly non-linear nature of the prepayment function. Non-parametric techniques are much better at detecting non-linearity and multivariate interaction. This article discusses how non-parametric kernel regression may be applied to loan level event histories to produce a better parametric model. By utilizing a parsimonious specification, a model can be produced that practitioners can use in valuation routines based on Monte Carlo interest rate simulation.

prepayment, valuation, mortgages, non-parametric

Abstract:
Housing policy in the United States has long supported homeownership yet variation persists across income groups. This paper employs recent mortgage origination data to focus on the revealed preferences of low-and-moderate income (LMI) households in home purchase mortgage choice. We identify the factors associated with conventional conforming, FHA, Nonprime, and specially-targeted programs. Empirical results show that individual credit characteristics and financial factors, including pricing, generally drive product choice with some variation evident when loans are originated through brokers. Results also indicate that targeted conventional programs effectively compete with government-insured products in the LMI segment.

housing finance, mortgage choice, low-and-moderate income

Abstract:
Call protection in debt contracts is ubiquitous in the bond market, customary in the commercial mortgage market, yet reviled and highly restricted in the residential mortgage market. We examine the reasons for these differences and use Monte Carlo techniques to calculate the economic value of call protection (prepayment penalties) in residential mortgage contracts. Results explain why prepayment penalties are more prevalent in the subprime, compared to the prime, market segment. From the simulation results we also compute the reduction in equilibrium contract rates call protection allows and then verify those predictions using empirical using data on actual contracts, extending the existing literature. Results strongly suggest that call protection has significant economic value to both borrowers and lenders and that, hence, the trend toward greater restrictions on this contract feature is bad public policy.

mortgage, callable debt, prepayment, prepayment penalty

Abstract:
Much of the literature on pricing commercial mortgages and commercial mortgage-backed securities has assumed homogeneity in prepayment penalty structure. This study provides evidence that such an assumption is inappropriate and examines the effect of penalty structures observed in actual contracts. After conducting preliminary simulations, hazard models estimated from data on 1,165 multifamily mortgage loans are presented to show how empirical prepayment rates vary with alternative penalty structures. While yield maintenance and lockout provisions are relatively more effective than fixed or step down structures in reducing or postponing prepayment, none completely eliminates the risk. The empirical results generally confirm the theoretical findings of Kelly and Slawson (2001).

commercial mortgage, mortgage-backed security, prepayment penalty

Abstract:
Housing policy in the United States has long supported homeownership, yet variation persists across income groups. This article employs recent mortgage origination data to focus on the revealed preferences of low- and moderate-income (LMI) households in home purchase mortgage choice. I identify the factors associated with conventional conforming, FHA, nonprime and specially targeted programs. Empirical results show that individual credit characteristics and financial factors, including pricing, generally drive product choice, with some variation evident when loans are originated through brokers. Results also indicate that targeted conventional programs effectively compete with government-insured products in the LMI segment.

Abstract:
Mortgage brokers have grown in importance in the home mortgage origination process in recent years, suggesting they provide a valuable service matching borrowers and lenders, although their involvement has also been linked to the recent surge in mortgage defaults and foreclosures. As in other markets dominated by brokers, agents’ incentives are often poorly aligned with those with whom they do business, in this case both the lenders who bear the risks once the loan is originated and the consumer who assumes liability for the debt and contract terms. This paper describes the institutional arrangements under which mortgage brokers operate and empirically test whether loans originated by mortgage brokers are lower in cost than those that would be available directly from retail lenders. The results suggest that loans originated by brokers cost borrowers about 20 basis points more, on average, than retail loans and that this premium is higher for lower income and lower credit score borrowers.

Broker, Mortgage, origination

Abstract:
This paper studies the relationship between housing tenure and mortgage contract. We show that over a limited horizon, borrowers will have incentive to self-select into the appropriate mortgage product such that their fixed-rate period is directly related to their probability of moving. We empirically test the hypothesis based on actual housing tenure computed from a random sample of a large national database of repeat mortgage sales. We find that, after controlling for borrower characteristics, the hazards of 3/1, 5/1 and 7/1 ARMs, compared to FRM30, are predicted to be 28%, 14% and 11% higher respectively, while that of 10/1 ARMs is 9% lower.

mortgage contract, housing tenure

Abstract:
We develop a unique paired loan dataset containing information on multiple conventional conforming mortgage loans of households to examine home equity extraction decisions over the period 2000-2006. The main question addressed is how much households borrow when refinancing their current mortgage debt in a cash-out transaction. We also provide estimates of the marginal effect of certain borrower characteristics. Results contribute both to the literature on refinancing behavior and the role of house price appreciation in providing funds that may be used for consumer spending or other purposes.

Cash our refinance, equity extraction

Abstract:
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.

appraisal, mortgage, default, house price indices

Abstract:
We assess nonparametric kernel density regression as a technique for estimating mortgage loan prepayments - one of the key components in pricing highly volatile mortgage-backed securities and their derivatives. The highly non-linear and so-called "irrational" behavior of the prepayment function lends itself well to an estimator that is free of both functional and distributional assumptions. The technique is shown to exhibit superior out-of-sample predictive ability compared to both proportional hazards and proprietary practitioner models. Moreover, the best kernel model provides this improved predictive power utilizing a more parsimonious specification in terms of both data and covariates. We conclude that the technique may prove useful in other financial modeling applications, such as default modeling, and other derivative pricing problems where highly non-linear relationships and optionality exist.

mortgage, prepayment, nonparametric

Abstract:
This paper empirically examines several open questions regarding prepayment risk in adjustable rate mortgages (ARMs), using loan-level data. Results support the teaser rate and adjustment date effects implied by the theoretical option pricing model of Kau, Keenan, Epperson and Muller (1993). In addition, we find that deeply teased ARMs do have greater prepayment risk, contrary to the results of Green and Shilling (1997).

Abstract:
This paper surveys the effects of technology on mortgage finance over the period 1990-2000, from an industry perspective. Important innovations in the three functional areas of origination, servicing, and portfolio management are identified and their effects discussed. Improvements in information technology, especially in processor speeds, data storage media, networking, and telephony, have reduced transaction costs, accelerated implementation of new risk management and valuation techniques, increased productivity, and allowed development an entirely new origination channel, the Internet. The interactions of technological change with demographic, regulatory, and market forces will continue to transform the industry.

Abstract:
We assess nonparametric kernel density regression as a technique for estimating mortgage loan prepayments - one of the key components in pricing highly volatile mortgage-backed securities and their derivatives. The highly non-linear and so-called "irrational" behavior of the prepayment function lends itself well to an estimator that is free of both functional and distributional assumptions. The technique is shown to exhibit superior out-of-sample predictive ability compared to both proportional hazards and proprietary practitioner models. Moreover, the best kernel model provides this improved predictive power utilizing a more parsimonious specification in terms of both data and covariates. We conclude that the technique may prove useful in other financial modeling applications, such as default modeling, and other derivative pricing problems where highly non-linear relationships and optionality exist.

Abstract:
We focus on an agency problem encountered by mortgage lenders and investors in mortgage-backed securities when the underlying collateral is originated by third parties. Third parties, such as mortgage brokers, have economic incentives to encourage borrowers to refinance and, accordingly, their actions may affect asset values. We sketch the principal-agent problem and examine two sets of data. Results support the argument: loans originated by third parties are significantly more likely to prepay after controlling for other known determinants of termination risk. Moreover, third party loans are about three times as sensitive to refinancing incentives, compared to retail loans.

Abstract:
This paper surveys the literature on racial disparities in mortgage lending over the past twenty five years, including a discussion of the theoretical models, empirical methods, and data used to test for discrimination. Weaknesses in the models, methods, and data typically used together with results from simulation studies cast serious doubt on many of the claims made about discrimination in mortgage lending markets. In its conclusion the paper offers some proposals for new directions in research to better understand racial differences in mortgage usage.