Microfoundations of a mortgage prepayment function

This article focuses on the following question: how much of an interest rate decline is needed to justify refinancing a typical home mortgage? Modern option pricing theory is used to answer the question; this theory indicates that the answer depends upon several factors, which include the volatility of interest rates and the expected holding period of the borrower. The analysis suggests that the commonly espoused “rule of thumb” refinance if the interest rate declines by 200 basis points — is a fair approximation to the more precisely derived differential for many households. We also construct the prepayment behavior of a pool of mortgages in which the expected holding periods of the borrowers in the pool vary. The prepayment behavior of this simulated pool is used to generate a series of empirically testable hypotheses regarding the likely shape of an actual prepayment function and its determinants. Finally, actual prepayment data are used to estimate a hazard function that explains prepayment behavior. We find that the estimated model understates prepayment behavior relative to that predicted by the simulation model, which suggests that the simple option pricing model is not adequate to explain aggregate prepayment behavior.     

Optimal consumption,portfolio and life insurance rules for an uncertain lived individual in a continuous time model

A continuous time model for optimal consumption, portfolio and life insurance rules, for an investor with an arbitrary but known distribution of lifetime, is derived as a generalization of the model by Merton (1971). The classic Tobin-Markowitz separation theorem obtains with the mutual funds being identical to those obtained under the assumption of certain lifetime. The investor is found to have a ‘human capital’ component of wealth, which is independent of his preferences and risky market opportunities and represents the certainty equivalent of his future net (wage) earnings. Explicit solutions, which are linear in wealth, are found for the investor with constant relative risk aversion.     

Reliability of Asset Revaluations: The Impact of Appraiser Independence

In this paper we examine whether there are differences in the reliability of asset revaluations made by boards of directors versus independent (external) appraisers. We use a sample of recognized Australian asset revaluations. As a first step we examine the determinants of the choice between director-based revaluations and those undertaken by independent appraisers. We find that independent appraisers are more likely to be used for revaluations of land and buildings and directors are more likely for investments, plant and equipment and identifiable intangibles. We interpret this as evidence of firms harnessing directors' knowledge of asset specificities. We also find that firms with less independent boards are more likely to use independent appraisers. We interpret this as evidence of substitutability between governance mechanisms.As for differences in reliability, we find that revaluations of plant and equipment that are made by independent appraisers are more reliable than those by directors. However, we are unable to detect a difference for other classes of non-current assets. We define reliability in terms of ex-post adjustments of recognized value increases. Reliability is determined by an examination of the extent to which upward revaluations are subsequently reversed.     

Capital Structure Decisions in the Insurance Industry: Stocks versus Mutuals

Mutual insurers generally face higher costs of raising new capital than stock insurers. Other things being equal, the higher costs of raising capital should cause mutual insurers to have higher ex ante target capital to liability ratios than stock insurers. Mutual insurers' capital ratios also should be more sensitive to income than capital ratios for stock insurers and therefore adjust more slowly toward their long-run targets. We provide evidence concerning these issues using aggregate time series data for stock and mutual insurers during 1984–1999 and a large panel data set during 1991–1998. Our regressions provide strong evidence that annual changes in capital to liability ratios are more sensitive to income for mutual insurers than for stock insurers. We also provide evidence that mutual insurers' capital ratios are on average higher than those for stock insurers after controlling for several factors that could influence capital ratios.     

iShares Australia: a clinical study in international behavioral finance

Using iShares Australia returns as a proxy for the influence of overseas investors in the Australian market, we found that U.S.-based investors in the Australian market overreact to contemporaneous and lagged returns of the U.S. equity market, the U.S.-Australian dollar exchange rate, and past iShares Australia returns. In response to changing conditional risk, however, investors behave rationally: increasing (decreasing) expected risk is associated with falling (rising) prices. In light of these findings, we hypothesize that behavioral finance might explain the observed correlations between international equity markets.     

Property and Inflation: The Hedging Characteristics of U.K. Commercial Property, 1967–1994

This paper examines the statistical similarities between U.K. commercial property capital and rental values and the price level. Our aim is to determine whether commercial property is an inflation hedge and, if so, what type of inflation it hedges against. To answer these questions, we use both a multivariate unobserved components model and structural vector autoregressions. We find that commercial property is an inflation hedge but only a weak one. More specifically, we find that property offers some form of partial hedge against changes in the underlying inflation rate but not to either temporary or permanent changes to the price level. We also find that capital values offer a stronger hedge than rental values and that industrial and retail property account for most of this hedging capacity. We find no evidence that property responds differently to high or low inflation but we do find capital and rental values respond more to unexpected inflation than anticipated price changes.     

An Analysis of the Systemic Risks Posed by Fannie Mae and Freddie Mac and An Evaluation of the Policy Options for Reducing Those Risks

Fannie Mae and Freddie Mac are government-sponsored enterprises that are central players in U.S. secondary mortgage markets. Over the past decade, these institutions have amassed enormous mortgage- and non-mortgage-oriented investment portfolios that pose significant interest-rate risks to the companies and a systemic risk to the financial system. This paper describes the nature of these risks and systemic concerns and then evaluates several policy options for reducing the institutions’ investment portfolios. We conclude that limits on portfolio size (assets or liabilities) would be the most desirable approach to mitigating the systemic risk posed by Fannie Mae and Freddie Mac.