What motivates a subprime borrower to default?

This paper uses a real options approach to analyse the exercise of the default option embedded in mortgages. In particular, it examines a subprime household who borrows at a premium, but hopes to refinance at prime rates if their house appreciates. We show how these optimal default decisions can be used to calculate probabilities of default – an important input for risk management and pricing purposes. Numerical examples are provided, calibrated to US data. In a low interest rate environment, the credit-upgrade potential may discourage subprime borrowers from defaulting. However, default probabilities are highly sensitive to changes in interest rates and house prices. This provides a rational explanation for the prevalence of adjustable rate mortgages among subprime borrowers, and the subsequent large numbers of defaults, when interest rates rose and house prices declined.     

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.     

Effects of Bankruptcy Exemptions and Foreclosure Laws on Mortgage Default and Foreclosure Rates

This study analyzes the effects of state bankruptcy asset exemptions and foreclosure laws on mortgage default and foreclosure rates across different segments of the mortgage market. We found that the effects of these legal provisions are larger for subprime than for prime mortgages and larger for adjustable rate mortgages than for fixed rate mortgages. These results demonstrate that the effect of variation in bankruptcy exemptions and foreclosure laws is most pronounced in the most risky segments of the mortgage market, which are those that have been most affected by the continuing housing slump in the United States.     

House‐Price Expectations,Alternative Mortgage Products,and Default

The goal of this paper is to better understand the forces that spurred use of alternative mortgages during the housing boom. A theoretical model shows that, when future house‐price expectations become more favorable, reducing default concerns, mortgage choices shift toward alternative products, which are characterized by backloading of payments. The empirical work confirms this prediction by showing that an increase in past house‐price appreciation, which captures more favorable expectations for the future, raises the market share of alternative mortgages. In addition, the paper tests the fundamental presumption that backloaded mortgages are more likely to default, finding support for this view.     

A Model of Mortgage Default

In this paper, we solve a dynamic model of households' mortgage decisions incorporating labor income, house price, inflation, and interest rate risk. Using a zero‐profit condition for mortgage lenders, we solve for equilibrium mortgage rates given borrower characteristics and optimal decisions. The model quantifies the effects of adjustable versus fixed mortgage rates, loan‐to‐value ratios, and mortgage affordability measures on mortgage premia and default. Mortgage selection by heterogeneous borrowers helps explain the higher default rates on adjustable‐rate mortgages during the recent U.S. housing downturn, and the variation in mortgage premia with the level of interest rates.     

A Bayesian Multivariate Risk-Neutral Method for Pricing Reverse Mortgages

In this article, we propose a Bayesian multivariate framework to price reverse mortgages that involve several risks in both insurance and financial sectors (e.g., mortality rates, interest rates, and house prices). Our method is a multivariate extension of the Bayesian risk-neutral method developed by Kogure and Kurachi. We apply the proposed method to Japanese data to examine the possibility for a successful introduction of reverse mortgages into Japan. The results suggest a promising future for this new market.     

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.     

Focusing on Fannie and Freddie: The Dilemmas of Reforming Housing Finance

Fannie Mae and Freddie Mac are unique and controversial participants in the housing finance system of the United States. Because of these enterprises' federal government charters, the financial markets believe that the government would not allow Fannie and Freddie to fail to honor their debt obligations, and they are thereby able to borrow more cheaply in credit markets; in turn, they lower interest rates for residential mortgages. If the financial markets are right, however, Freddie and Fannie also create a contingent liability for the government. Though there are positive externalities from home ownership, the Fannie/Freddie route is far too broad and unfocused to address those externalities effectively. Privatization, accompanied by targeted federal assistance for potential first-time low- and moderate-income home buyers, would be a superior policy direction.     

Phasing out the GSEs

We develop a new model of the mortgage market that emphasizes the role of the financial sector and the government. Risk tolerant savers act as intermediaries between risk averse depositors and impatient borrowers. Both borrowers and intermediaries can default. The government provides both mortgage guarantees and deposit insurance. Underpriced government mortgage guarantees lead to more and riskier mortgage originations and higher financial sector leverage. Mortgage crises occasionally turn into financial crises and government bailouts due to the fragility of the intermediaries’ balance sheets. Foreclosure crises beget fiscal uncertainty, further disrupting the optimal allocation of risk in the economy. Increasing the price of the mortgage guarantee “crowds in” the private sector, reduces financial fragility, leads to fewer but safer mortgages, lowers house prices, and raises mortgage and risk-free interest rates. Due to a more robust financial sector and less fiscal uncertainty, consumption smoothing improves and foreclosure rates fall. While borrowers are nearly indifferent to a world with or without mortgage guarantees, savers are substantially better off. While aggregate welfare increases, so does wealth inequality.     

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.     

房价波动、金融稳定与最优宏观审慎政策

本文通过构建包含家庭住房抵押借款摩擦和银行贷款摩擦的动态随机一般均衡模型,重点考察了异质性冲击下房价波动对金融稳定的影响。研究发现,房价上涨会导致银行风险溢价及杠杆率显著上升,进而加剧金融体系的内在不稳定。为降低房价波动及维护金融稳定,选取两类宏观审慎政策工具进行逆周期调控实验,结果表明,在住房需求冲击下,金融管理部门应选取贷款价值比政策,且应对房贷积极调控,而对房价进行中性调控。在最终产品部门生产率冲击、房地产部门生产率冲击及跨期偏好冲击下,应选取资本充足率政策,但对房贷和房价调控力度的把握则存在差异。本研究为厘清房价波动对金融稳定的动态传导机制,以及金融管理部门如何选取宏观审慎政策工具以稳定房价并降低系统性金融风险提供了启示。     

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.     

Forced Asset Sales and the Concentration of Outstanding Debt: Evidence from the Mortgage Market

We provide evidence that lenders differ in their ex post incentives to internalize price‐default externalities associated with the liquidation of collateralized debt. Using the mortgage market as a laboratory, we conjecture that lenders with a large share of outstanding mortgages on their balance sheets internalize the negative spillovers associated with the liquidation of defaulting mortgages and thus are less inclined to foreclose. We provide evidence consistent with our conjecture. Arguably as a consequence, zip codes with a higher concentration of outstanding mortgages experience smaller house prices declines. These results are not driven by unobservable zip code or lender characteristics.     

房价调控、地方政府债务与宏观经济波动

在地方政府债务高企的背景下,房价调控能否使资本流向非房地产部门？房价调控如果触发地方政府债务违约,宏观政策应如何应对？本文基于中国宏观经济的特征事实,引入地方政府的土地财政行为,将房价变动与地方政府的偿债能力联系起来。研究表明,由于地方政府依赖土地出让和土地抵押贷款筹集收入,房价管控导致的地价下降会带来地方政府收入的下降,直接影响地方政府的偿债能力。如果地方政府债务不出现违约,那么房价管控带来的地价下降会降低地方政府从金融部门获得的抵押融资额,使非基建部门的融资成本下降,非基建部门投资和产出上升。而如果调控房价带来的地价下降导致地方政府出现债务违约,金融部门资产受损,使金融中介减少贷款和提高贷款成本,带来整个社会的信贷紧缩,经济中各个部门的产出大幅下降。进一步的政策分析表明,有必要在避免地方政府债务违约的同时,使用财政资金补充银行资本金等多种方式稳定金融中介的资产负债表,从而将房价调控对经济的负面影响程度降到最低。     

住房价格、金融稳定与宏观审慎政策

本文通过建立包含异质性家庭、异质性厂商和金融机构的DSGE模型,分析对预期房价作出反应的货币政策和宏观审慎政策的传导机制和政策效果,研究不同政策的选择和协调问题。研究发现,首先,由于政策的作用范围不同,不同政策会对金融稳定和经济稳定产生不同影响。对预期房价作出反应的货币政策能够抑制住房需求和信贷供给,但也会抑制消费需求和产出;而对预期房价作出反应的逆周期LTV政策和逆周期资本充足率政策在应对房价波动导致的金融稳定问题时更加有的放矢。其次,外生冲击的来源会影响政策的选择和协调——当经济波动来源于需求冲击时,固定LTV政策搭配逆周期资本充足率的宏观审慎政策、不对预期房价作出反应的货币政策表现最优;当经济波动来源于供给冲击时,固定LTV政策搭配逆周期资本充足率的宏观审慎政策、对预期房价作出反应的货币政策表现最优。     

Subprime mortgage design

This paper offers evidence on the design of subprime mortgages as bridge-financing products. We show that the viability of subprime mortgages was uniquely predicated on the appreciation of house prices over short horizons. High rates of early prepayments on subprime mortgages suggest the use of prepayments as an exit option. This paper argues that high early defaults on post-2004 originations can be explained when one considers high early prepayment rates for pre-2004 originations.     

Modeling the behavior of real asset prices

Recently there has been much research treating housing and other real assets as financial claims, primarily in order to value their derivative assets, such as mortgages and mortgage-backed securities. Real asset prices are then typically modeled as a lognormal process, in the same manner that has traditionally been applied to firm value. The service flow or implicit value of a house is thus considered, in analogy with stock dividends, to be a fixed proportion of the fluctuating house price. We consider the appropriateness of this formulation and draw some distinctions between real assets, such as a house, and investment enterprises, such as a firm. We then propose an alternative method of formulating the service flow and the price of real assets which seems more appropriate to the economic characteristic of such assets.     

House Prices and Government Spending Shocks

We show that dynamic stochastic general equilibrium (DSGE) models with housing and collateralized borrowing predict a fall in house prices following positive government spending shocks. By contrast, we show that house prices in the United States rise persistently after identified positive government spending shocks. We clarify that the incorrect house price response is due to a general property of DSGE models—approximately constant shadow value of housing—and that modifying preferences and production structure cannot help in obtaining the correct house price response. Properly accounting for the empirical evidence on government spending shocks and house prices using a DSGE model therefore remains a significant challenge.     

Release of a liquidity regulation: What do we learn for credit and house prices?

This paper studies the effects of the release of a limit on banks’ maturity transformation – akin to the Net Stable Funding Ratio – for mortgage supply and house prices. After the regulatory easing, credit supply increased only for the banks that were previously constrained by the regulation and not for the others. We also show that the expansion in mortgages triggered by the deregulation accelerated house prices. The effect was channeled through higher demand for housing and the relaxation of borrowers’ financial constraints. Even though the impact of the credit supply shock persisted, the interaction between credit and house prices was not conducive to a housing market overheating.     

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.