Do Assumptions About Factor Structure Matter in Empirical Tests of the APT?

The effect of assumptions about factor structure on empirical tests of multifactor models such as the Arbitrage Pricing Policy Theory has received little attention in the literature. Using data on securities traded on the London Stock Exchange, we examine whether returns are best described by an approximate factor structure and whether assumptions about correlations across idiosyncratic returns have a significant impact on estimated prices of risk and their significance. Our findings suggest that returns are best described by an approximate factor structure and, if this is taken into account when empirically testing the APT, six factors carry significant prices of risk. However, if a strict factor structure is imposed, no factors carry significant prices of risk. These findings suggest that assumptions about factor structure matter in empirically testing the APT.     

A Critical Reexamination of the Empirical Evidence on the Arbitrage Pricing Theory

This paper demonstrates that the Roll and Ross (RR) and other previously published tests of the APT are subject to several basic limitations. There is a general nonequivalence of factor analyzing small groups of securities and factor analyzing a group of securities sufficiently large for the APT model to hold. It is found that as one increases the number of securities, the number of “factors” determined increases. This increase in the number of “factors” with larger groups of securities cannot readily be explained by a distinction between “priced” and “nonpriced” risk factors as it is impermissible to carry out tests on whether a given “risk factor is priced” using factor analytic procedures.     

An empirical analysis of the incentives to engage in costly information acquisition: The case of risk arbitrage

In order for security prices to be informationally efficient, incentives must exist for traders to engage in costly information acquisition. This paper provides empirical evidence on this proposition. We observe that risk arbitrageurs (i.e., market participants who trade in securities of firms that are involved in mergers, tender offers, and voluntary liquidations) are able to generate private information regarding the success or failure of corporate reorganizations. Moreover, risk arbitrageurs earn substantial returns on their trading activities. These results suggest that security prices are sufficiently noisy to create incentives for costly information acquisition.     

Intermarket efficiency: An application of interbattery APT to mortgage-backed securities

Increasing popularity of investments in mortgage-backed securities has led to closer integration of the mortgage market into traditional capital markets. Using monthly returns during 1982–1988 for common stocks, Treasury bonds and GNMA and FHLMC mortgage-backed securities, the interbattery factor analytic Arbitrage Pricing Theory of (Cho, 1984) is used to test five hypotheses for intramarket and intermarket integration. Results indicate that three to five common factors are found within the same security market, while only one to three factors are found common between different markets.The APT could not be rejected within the same security market, but was rejected in most intermarket comparisons. While risk-free rates are found to differ between markets, the risk premium tests are conclusive indicators of integration. Our results support claims that the stock, bond, and the mortgage-backed securities markets are integrated.     

The Subprime Panic*

Understanding the ongoing credit crisis or panic requires understanding the designs of a number of interlinked securities, special purpose vehicles, and derivatives, all related to subprime mortgages. I describe the relevant securities, derivatives, and vehicles to show: (1) how the chain of interlinked securities was sensitive to house prices; (2) how asymmetric information was created via complexity; (3) how the risk was spread in an opaque way; and (4) how trade in the ABX indices (linked to subprime bonds) allowed information to be aggregated and revealed. These details are at the heart of the origin of the Panic of 2007. The events of the panic are described.     

The behavior of stock prices on LDC markets

The paper investigates the behavior of stock prices for a group of well established and newly emerging LDC securities markets. The results suggest the probability distributions to be consistent with a lognormal distribution with some securities exhibiting non-stationary variance. LDC markets, even though not as efficient as major DC markets, are quite comparable to the smaller European markets and the behavior of security prices as reported in this study appears to be generalizable for the heavily traded segments of LDC markets.     

Endogenous informed trading in the presence of trading costs: Theory and evidence

The basic premise of the model we propose is that market frictions (trading costs) force traders with market-wide information to strategically choose which securities to trade in. We study the effect of recognizing trading costs on the choices of informed traders and the resulting statistical properties of security prices. Specifically, we show that (1) stocks with intermediate β's have the least informative prices, even though they are traded by the greatest number of informed traders; (2) for high β securities, the contemporaneous correlation of prices is close to the correlation in fundamental values; (3) a security with a higher β, higher volume of liquidity trading and lower idiosyncratic variance is more likely to lead another security. With market capitalization as a proxy for the level of liquidity trading, these specific predictions of the model on the lead–lag relationship are also shown to be strongly supported by the data.     

The pricing of supershares

The new ‘supershare’ securities proposed by Hakansson (1977, 1976) are subject to the same sort of rickless-hedge combinations as are other forms of secondary securities such as stock options. In consequence, the prices of supershares must, even in the absence of distributional assumptions, obey certain pricing relationships with each other and with the underlying primary security. When the primary security is assumed in addition to follow a geometric Brownian motion process, exact supershare valuation formulae of the Black-Scholes (1973) type are obtained. The ‘hedge portfolio algebra’ of Garman (1976) is employed to make the analysis concise.     

Alternate approach to unify CAPM and APT

We utilize the joint elliptical distribution to model a multi-factor return generating process and derive an equilibrium multi-beta capital asset pricing model (CAPM) in which the market portfolio and a set of nonelliptical factors are sufficient to price all financial assets. Most important, it is shown that the market portfolio, while generally nonelliptical, can proxy all elliptical factors and hence: including elliptical factors in addition to the market portfolio in the pricing equation contribute nothing to asset pricing. While the representative investor prices the exposure of aggregate wealth to various nonelliptical systematic risk factors, individual securities are priced in accordance to their contributions to different aspects of the risk of aggregate wealth. The present model collapses to the Sharpe-Lintner CAPM when either the market investor is neutral to nonelliptical risk factors or when all risk factors follow a joint spherical distribution. When residuals cancel out of the market portfolio, the present model collapses to Conner (1984) pricing model.     

The cross-section of dynamics in idiosyncratic risk

This paper investigates change in idiosyncratic volatility estimated by individual security. We find that a significant portion of securities contains long periods of increasing or decreasing idiosyncratic risk. The series of idiosyncratic risk though are unlikely to have a life-long deterministic trend, and can be often characterized by a long memory process. Our evidence suggests that the proportions of securities with rising and declining risk continuously change, which in turn affects fluctuations of the market average. This evidence implies that an average idiosyncratic risk may not be a good representative of the dynamics in risk of a given security. We demonstrate that the companies with an increasing idiosyncratic risk tend to have deteriorating performance, and investigate factors behind these empirical observations.     

The Cost of Deposit Insurance for Privately Held Banks: A Market Comparable Approach

Previous empirical studies that use an option pricing model to estimate deposit insurance costs have been limited to banks that issue publicly traded securities: a bank's security prices are used to infer its risk characteristics. However, if deposit insurance costs are needed for privately held banks, as would be the case under a system of risk-based insurance premiums, then an alternative method is required. This paper presents a “market comparable” approach for valuing private banks' deposit insurance. The approach first uses information on public depository institutions to identify the statistical relationships between a bank's supervisory accounting data and its risk characteristics derived from equity market data. Second, it uses these relationships to predict the risk characteristics of a private depository institution based on its supervisory accounting data. This approach is applied to over 7000 private banks and thrifts to estimate their risk characteristics and their implied risk-neutral and physical probabilities of insolvency. For the vast majority of institutions, these risk characteristics and insolvency probabilities are within a reasonable range.     

The association between accounting earnings and security returns for large and small firms

The differential information hypothesis advanced by Atiase (1980) states that information production and dissemination by private parties for the purpose of identifying mispriced securities is an increasing function of firm size. This study examines two corollaries of that hypothesis. First, security prices of large firms anticipate accounting earnings earlier than security prices of small firms. Second, for a given level of ‘unexpected’ earnings, the cumulative abnormal returns of small firms exceed those of large firms. The results are generally consistent with Atiase's hypothesis.     

我国证券公司治理绩效的因子分析

证券公司是资本市场最重要的行为主体之一,我国证券公司虽已建立了董事会、监事会、独立董事等现代公司治理框架,但在实际运作中其职能行使上存在许多不规范的地方。2008年金融危机告诫我们,不仅需要提高证券公司的风险防范机制,更需要建立完善的公司治理结构,促使证券公司风险防范机制作用顺利发挥。通过因子分析法将证券公司内部治理变量综合成为四个因子,即规模激励因子、结构因子、监管因子和独立性因子,进而分析内部治理因子对证券公司经营绩效的影响。     

Measuring security price performance

Event studies focus on the impact of particular types of firm-specific events on the prices of the affected firms' securities. In this paper, observed stock return data are employed to examine various methodologies which are used in event studies to measure security price performance. Abnormal performance is introduced into this data. We find that a simple methodology based on the market model performs well under a wide variety of conditions. In some situations, even simpler methods which do not explicitly adjust for marketwide factors or for risk perform no worse than the market model. We also show how misuse of any of the methodologies can result in false inferences about the presence of abnormal performance.     

Implied Equity Duration: A New Measure of Equity Risk

Duration is an important and well-established risk characteristic for fixed income securities. We use recent developments in financial statement analysis research to construct a measure of duration for equity securities. We find that the standard empirical predictions and results for fixed income securities extend to equity securities. We show that stock price volatility and stock beta are both positively correlated with equity duration. Moreover, estimates of common shocks to expected equity returns extracted using our measure of equity duration capture a strong common factor in stock returns. Additional analysis shows that the book-to-market ratio provides a crude measure of equity duration and that our more refined measure of equity duration subsumes the Fama and French (1993) book-to-market factor in stock returns. Our research shows how structured financial statement analysis can be used to construct superior measures of equity security risk.     

Corporate bond yields and returns: a survey

Corporate bonds offer higher yields than government bonds with similar maturity. This higher reward comes at the cost of higher risk. The question then arises of how this risk is priced into corporate bonds. This literature review provides a classification and summary of papers studying corporate bond prices and the premium they offer to investors over the return on risk-free securities. The review ranges from theoretical models to empirical determinants of corporate bond prices. A specific section is dedicated to the liquidity impact as this component has received special attention.

     

Estimating Oil Risk Factors Using Information from Equity and Derivatives Markets

We introduce a novel approach to estimating latent oil risk factors and establish their significance in pricing nonoil securities. Our model, which features four factors with simple economic interpretations, is estimated using both derivative prices and oil‐related equity returns. The fit is excellent in and out of sample. The extracted oil factors carry significant risk premia, and are significantly related to macroeconomic variables as well as portfolio returns sorted on characteristics and industry. The average nonoil portfolio exhibits a sensitivity to the oil factors amounting to a sixth (in magnitude) of that of the oil industry itself.     

Arbitrage-free credit pricing using default probabilities and risk sensitivities

The relation between physical probabilities (rating) and risk-neutral probabilities (pricing) is derived in a large market with a quasi-factor structure. Factor sensitivities and default probabilities are obtainable for all kinds of credits on historical rating data. Since factor prices can be backed out from market data, the model allows the pricing of non-marketable credits and structured products thereof. The model explains various empirical observations: credit spreads of equally rated borrowers differ, spreads are wider than implied by expected losses, and expected returns on CDOs must be greater than their rating matched, single-obligor securities due to the inherent systematic risk.