The Government‐Sponsored Enterprises and the Mortgage Crisis: The Role of the Affordable Housing Goals

I use regression discontinuity analysis to measure the effect of one of the Affordable Housing Goals, the Underserved Areas Goal (UAG), on the number of whole single‐family mortgages purchased by Fannie Mae and Freddie Mac (GSEs) in undeserved census tracts for 1996–2002. Focusing additionally on tracts that became UAG‐eligible in 2005–2006, I measure the effect of the UAG during peak years for the subprime market. The results suggest a small UAG effect and challenge the view that the goals caused the GSEs to supply substantially more credit to high‐risk borrowers than they otherwise would have supplied during the subprime boom.     

The Impact of the Home Valuation Code of Conduct on Appraisal and Mortgage Outcomes

The accuracy of appraisals came into scrutiny during the housing crisis, and a set of policies and regulations was adopted to address the conflict‐of‐interest issues in the appraisal practices. In response to an investigation by the New York State Attorney General's office, the Home Valuation Code of Conduct (HVCC) was agreed to by Fannie Mae, Freddie Mac and the Federal Housing Finance Agency. Using unique data sets that contain both approved and nonapproved mortgage applications, this study provides an empirical examination of the impact of the HVCC on appraisal and mortgage outcomes. The results suggest that the HVCC has led to a reduction in the probability of inflated valuations, although valuations remained on average inflated, and induced a significant increase in the incidence of low appraisals. The well‐intentioned HVCC rule made it more difficult to obtain mortgages to purchase homes during the housing price crash, possibly exacerbating the fall in prices.     

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.     

The GSE Implicit Subsidy and the Value of Government Ambiguity

The housing-related government-sponsored enterprises (GSEs) Fannie Mae and Freddie Mac have an ambiguous relationship with the federal government. Most purchasers of the GSEs' debt securities believe that this debt is implicitly backed by the U.S. government despite the lack of a legal basis for such a belief. In this article, I estimate how much GSE shareholders gain from this ambiguous government relationship. I find that (i) the government's ambiguous relationship with Fannie Mae and Freddie Mac imparts a substantial implicit subsidy to GSE shareholders, (ii) the implicit government subsidy accounts for much of the GSEs' market value and (iii) the GSEs would hold far fewer of their mortgage-backed securities in portfolio and their capital-to-asset ratios would be higher if they were purely private.     

The Measurement and Determinants of Single-Family House Prices

We assess the conceptual and empirical features of a number of house price series for the United States. We then calculate a measure of the net up-grading of the existing stock of houses that took place during the 1950–1989 period and adjust price indexes for this net increase in quality. Judgments about the trend, volatility, and determinants of house prices are shown to depend crucially on which price series is used. The Freddie Mac upgrade-adjusted house price measure rose 5.7% over the past four decades, falling 7.7% from 1950 through 1970 before rising 14.5% from 1970 through 1989. Real house prices declined in the early 1980s due to the increase in real after-tax interest rates and the decline in real materials costs. The recovery of house prices in the late 1980s is attributed to lower unemployment and real after-tax interest rates and particularly to demographic factors associated with the aging of baby boomers.     

Mortgage Default Risks and the 1971 San Fernando Earthquake

The paper is based on a study of mortgage default risks associated with natural disasters. These risks are faced by holders of mortgages when forced by default to acquire damaged properties. A sample of residential mortgage properties damaged in the 1971 San Fernando, California earthquake is studied. Some of the mortgagors defaulted while others did not. The paper identifies and analyzes those variables associated with default using discriminant and probit regression analysis. The study concentrates on earthquake exposures in California, but has implications for all major disasters.     

What Moves the Mortgage‐Backed Securities Market?

Using a vector autoregressive model with monthly data from 1988 through 2001, this study investigates the factors that drive the excess returns on a widely followed mortgage-backed securities (MBS) index. We find that eight important economic variables (industrial productions, new home sales, bond horizon premium, bond quality premium, mortgage rate, refinancing proxy, general stock market index and world bond market index) appear to move the excess returns on MBS. Impulse response analysis and variance decomposition further indicate a strong dynamic relationship between MBS excess returns and changes in these economic variables. Additional analysis of Freddie Mac and Fannie Mae MBS also indicates that the risk of the MBS guarantor is an important determinant of the MBS return dynamics after the creation of the Office of Federal Housing Enterprise Oversight.     

New Evidence on Home Prices from Freddie Mac Repeat Sales

The weighted repeat sales price index methodology recently reported in Case and Shiller [5] [6] is applied to a dataset of over eight million loans bought by the Federal Home Loan Mortgage Corporation over the last twenty years. Regional price indices are reported and compared to indices from other sources. Statistical issues in the creation of the index, both technical and due to sample selectivity of the Freddie Mac dataset, are extensively discussed. It is found that the new index grows at a rate similar to other indices up until 1985, after which time it grows at a significantly higher rate.     

Differential Access to and Pricing of Home Mortgages: 2004 through 2009

This article documents trends and drivers of the residential mortgage market during the years 2004 through 2009, specifically focusing on the access to and pricing of mortgages originated by African‐American and Hispanic borrowers, and by borrowers living in low‐income and minority communities. Our analysis relies on a rich set of proprietary data that allow more expanded insights than can be obtained from the Home Mortgage Disclosure Act (HMDA) alone. We show that access to mortgage credit increased between 2004 and 2006 for the borrowers we focus on in our study and declined dramatically thereafter. Trends in access to credit were driven primarily by the changing credit mix of mortgage applicants and secondarily by the replacement of the Federal Housing Administration (FHA) for subprime as the dominant mode of nonprime originations and tighter underwriting standards. Throughout our entire period of study, these borrowers also consistently paid higher prices for their mortgages; however, the extent of this differential varied considerably over time and across groups. These pricing trends were driven primarily by changes in the FHA and subprime shares as well as by the market's increasingly aggressive pricing of credit risk.     

Interest-Rate Volatility, Basis Risk and Heteroscedasticity in Hedging Mortgages

This paper investigates the validity of the OLS regression to estimate the hedge ratio for mortgages (GNMA) and provides alternative methodologies. In particular, this paper is concerned with the variance structure (conditional and unconditional heteroscedasticities) and the misspecification (nonlinearities) of the simple linear regression model for direct as well as cross-hedging. Using data on spot prices of GNMA and futures prices of GNMAs and T-bills for the period September 1979 to January 1985, we show that there exists significant heteroscedasticity particularly for cross-hedging, and nonlinearity between cash and futures prices for direct as well as cross-hedging. Alternative hedge ratio estimates are provided using the Box-Cox transformation model and an autoregressive conditional heteroscedastic (ARCH) Model.     

Home Ownership,Household Leverage and Hyperbolic Discounting

I examine tenure and mortgage choice in an equilibrium model in which households make decisions as if they discount hyperbolically rather than exponentially. Overall, hyperbolic discounting does not seem to explain the high rates of home ownership or portfolio concentration in housing in the data. I then study the choice between mortgages that require a substantial down payment and mortgages that require no down payment. Allowing households access to no‐down‐payment mortgages exacerbates rather than mitigates the undersaving of hyperbolic discounters. However, even when households discount hyperbolically, welfare is higher when households have access to no‐down‐payment mortgages.     

Efficiency in the Mortgage Market: The Borrower's Perspective

This paper uses mortgage history data from the Federal Home Loan Mortgage Corporation to analyze the prepayment behavior of homeowners and to test whether borrowers exercise their prepayment options in a manner consistent with contingent claims models. A variety of hazard models are estimated from individual data on more than 6000 mortgages issued during the 1976–1980 period. In these models, it is clear that the extent to which the prepayment option is "in the money" has a strong effect on behavior. However, it is less clear that the option is exercised quite as ruthlessly as the theory predicts.     

FNMA Mortgage Purchase Commitments As Put Options: An Empirical Examination

The Federal National Mortgage Association (FNMA) auctions commitments to purchase mortgages. An examination of the terms of the commitment contract shows that these commitments are actually put options on mortgages. The contract is unusual, however, in that the price of the commitment is a fixed percentage of the value of the mortgages. In the auction, the dealers effectively bid the exercise price at which they would be willing to pay the fixed commitment price.
In this paper, we study the economics of the FNMA auction. We use a two-state approximation to the American put pricing model for interest-dependent securities to examine the behavior of the auction results. We find that the model performs reasonably well for several years — giving results which are, on the average, correct — and then, quite abruptly, the performance of the model deteriorates. Some possible reasons for this result are then examined.     

Simulations of Savings Associations Using Alternative Mortgage Instruments

This paper reports on the development and use of a deterministic, accounting identity, simulation computer model of a federally chartered savings and loan association to observe the effect upon earnings and net worth growth, over the 1964 to 1974 period, of the use of various alternative mortgage instruments. Experiments were conducted on several kinds of variable rate mortgages, graduated payment mortgages, and price level adjusted mortgages; various interest reference rates were tested along with alternative systems of constraining VRM changes, alternative graduation rates, and various systems for paying interest to savers.     

Competition under capacitated dynamic lot-sizing with capacity acquisition

Lot-sizing and capacity planning are important supply chain decisions, and competition and cooperation affect the performance of these decisions. In this paper, we look into the dynamic lot-sizing and resource competition problem of an industry consisting of multiple firms. A capacity competition model combining the complexity of time-varying demand with cost functions and economies of scale arising from dynamic lot-sizing costs is developed. Each firm can replenish inventory at the beginning of each period in a finite planning horizon. Fixed as well as variable production costs incur for each production setup, along with inventory carrying costs. The individual production lots of each firm are limited by a constant capacity restriction, which is purchased up front for the planning horizon. The capacity can be purchased from a spot market, and the capacity acquisition cost fluctuates with the total capacity demand of all the competing firms. We solve the competition model and establish the existence of a capacity equilibrium over the firms and the associated optimal dynamic lot-sizing plan for each firm under mild conditions.     

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.     

Pricing Default Risk in Mortgages

This paper examines the valuation of fixed-rate mortgages and the pricing of insurance against default on such mortgages. Both the mortgage and the insurance are treated as compound European put options. A put is the right, but not the obligation, to turn over an asset to another party for a specified payment, and being a European put indicates that this can only occur at a specified expiration date. The mortgage contract, and hence the insurance on it, fit into a European option framework because no rational borrower would ever choose to default until a payment is due. Mortgages are compound options in nature because at each payment data prior to the last one, the borrower either defaults or purchases a new option to default at the next payment date by making the scheduled payment. Since the current value of the mortgage is affected by options to default in the future, the problem is solved working backwards in time with the value of later options feeding into the earlier ones, so that the process builds on itself in a recursive fashion. Using familiar arguments from option-pricing theory, the value of any of the assets in the model is expressed as the solution to a partial differential equation, where the terms of the contract yield the appropriate terminal conditions. Standard numerical procedures are then used to produce the value of the mortgage and the insurance under various economic conditions. The simulations indicate that the prime determinants of the value of the assets considered are the volatility of the house price and the volatility of the spot interest rate. Sensitivity tests show that changing either of these parameters affects the results substantially more than any of the other parameters examined. The paper completely analyzes the default option and insurance against default on the mortgage. It is one part of a complete model of fixed-rate mortgages that would allow for both prepayment and default and treat the interaction of the two options. The general approach outlined in this paper can be used to develop such a model as well as to value any mortgage-related security. In light of the increasing variety and the complexity of such instruments in the market today, the presentation of our approach to these valuation problems is perhaps the most important contribution of the paper.     

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.     

Prepayment Behavior of Dutch Mortgagors: An Empirical Analysis

The suboptimal exercise of the prepayment option in a mortgage is relevant for mortgage pricing and the management of a mortgage portfolio. Construction of an accurate prepayment model requires quantification of driving factors such as seasoning, seasonality, refinance incentive and burnout. We focus on Dutch mortgages but also discuss the Dutch market in a European setting. Within the euro-denominated MBS market, the Dutch market is often referred to as the benchmark market. In our application we include typical Dutch market and contract characteristics such as the annual penalty-free prepayment of 10 to 20% of the original loan amount. We use loan-level historical data on mortgages originated between January 1989 and June 1999 to estimate separate models for two popular redemption types: savings mortgages and interest-only mortgages. In both models we allow for suboptimal prepayment behavior. The results clearly indicate that prepayment rates depend on interest rates and the age of the mortgage contract. Moreover, we find that burnout is an important element in describing the prepayment behavior of Dutch mortgagors.     

Unobserved Heterogeneity in Models of Competing Mortgage Termination Risks

This article extends unobserved heterogeneity to the multinomial logit (MNL) model framework in the context of mortgages terminated by refinance, move or default. It tests for the importance of unobserved heterogeneity when borrower characteristics such as income, age and credit score are included to capture lender-observed heterogeneity. It does this by comparing the proportional hazard model to MNL with and without mass-point estimates of unobserved heterogeneous groups of borrowers. The mass-point mixed hazard (MMH) model yields larger and more significant coefficients for several important variables in the move model, whereas the MNL model without unobserved heterogeneity performs well with the refinance estimates. The MMH clearly dominates the alternative models in sample and out of sample. However, it is sometimes difficult to obtain convergence for the models estimated jointly with mass points.