Optimal commodity asset allocation with a coherent market risk modeling

This paper fills a fundamental gap in commodity price risk management and optimal portfolio selection literatures by contributing a thorough reflection on trading risk modeling with a dynamic asset allocation process and under the supposition of illiquid and adverse market settings. This paper analyzes, from a portfolio managers' perspective, the performance of liquidity adjusted risk modeling in obtaining efficient and coherent investable commodity portfolios under normal and adverse market conditions. As such, the author argues that liquidity risk associated with the uncertainty of liquidating multiple commodity assets over given holding periods is a key factor in formalizing and measuring overall trading risk and is thus an important component to model, particularly in the wake of the repercussions of the recent 2008 financial crisis. To this end, this article proposes a practical technique for the quantification of liquidity trading risk for large portfolios that consist of multiple commodity assets and whereby the holding periods are adjusted according to the specific needs of each trading portfolio. Specifically, the paper proposes a robust technique to commodity optimal portfolio selection, in a liquidity-adjusted value-at-risk (L-VaR) framework, and particularly from the perspective of large portfolios that have both long and short positions or portfolios that consist of merely pure long trading positions. Moreover, in this paper, the author develops a portfolio selection model and an optimization-algorithm which allocates commodity assets by minimizing the L-VaR subject to applying credible operational and financial constraints based on fundamental asset management considerations. The empirical optimization results indicate that this alternate L-VaR technique can be regarded as a robust portfolio management tool and can have many uses and applications in real-world asset management practices and predominantly for fund managers with large commodity portfolios.     

The Three‐Factor Model: A Practitioner's Guide

The three‐factor model (3FM) has slowly but steadily become a popular alternative to the CAPM for measuring risk from the perspective of both corporate finance and portfolio management. The evidence clearly shows a negative relationship between market capitalization and returns, and a positive relationship between the book‐to‐market ratio and returns. Under the assumption that size and value are risk factors, the 3FM incorporates a market risk premium, a size premium, and a value premium into a model that aims to assess risk in a more comprehensive way, and ultimately to provide a more reliable estimation of required return. The required return produced by the 3FM has corporate finance applications (such as cost of capital estimation, project evaluation, and firm valuation) as well as portfolio management applications (such as performance evaluation). This article discusses the foundations and intuition behind the 3FM, as well as its application to the estimation of the cost of equity and excess returns.     

The relation between stock returns and short-term interest rates

This study examines the relation between the expected returns on common stocks and short-term interest rates. Using a two-factor model of stock returns, we show that the expected returns on common stocks are systematically related to the market risk and the interest-rate risk, which are estimated as the sensitivity of common-stock excess returns to the excess return on the equally weighted market index and to the federal fund premium, respectively. We find that the interest-rate risk for small firms is a significant source of investors' portfolio risk, but is not properly reflected in the single-factor market risk. We also find that the interest-rate risk for large firms is “negative” in the sense that the market risk estimated from the single-factor model overstates the true risk of large firms. An application of the Fama-MacBeth methodology indicates that the interest-rate risk premium as well as the market's risk premium are significant, implying that both the market risk and the interest-rate risk are priced. We show that the interest-rate risk premium explains a significant portion of the difference in expected returns between the top quintile and the bottom quintile of the NYSE and AMEX firms. We also show that the turn-of-the-year seasonal is observed for the interest-rate risk premium; however, the risk premium for the rest of the year is still significant, although small in mangitude.     

Allocate Capital and Measure Performances in a Financial Institution

This paper provides a model for allocating capital and measuring performances for financial institutions. The methodology relates the economic valuation of the balance sheet to the market value of the firm. In so doing, each business unit is evaluated on an economic basis, and the capital allocated to these units is related to the risk premiums that the market demands. The paper's results have broad applications for corporate managers, risk managers, and other market participants in managing financial institutions to increase shareholders' value.     

The price of power: The valuation of power and weather derivatives

Pricing contingent claims on power presents numerous challenges due to (1) the unique behavior of power prices, and (2) time-dependent variations in prices. We propose and implement a model in which the spot price of power is a function of two state variables: demand (load) and fuel price. In this model, any power derivative price must satisfy a PDE with boundary conditions that reflect capacity limits and the non-linear relation between load and the spot price of power. Moreover, since power is non-storable and demand is not a traded asset, the power derivative price embeds a market price of risk. Using inverse problem techniques and power forward prices from the PJM market, we solve for this market price of risk function. During 1999–2001, the upward bias in the forward price was as large as $50/MWh for some days in July. By 2005, the largest estimated upward bias had fallen to $19/MWh. These large biases are plausibly due to the extreme right skewness of power prices; this induces left skewness in the payoff to short forward positions, and a large risk premium is required to induce traders to sell power forwards. This risk premium suggests that the power market is not fully integrated with the broader financial markets.     

Estimating the time Varying Components of international stock markets' risk

In this study an alternative approach for assessing securities' risk is applied. Various authors have argued that security returns are not homoskedastic but exhibit variation over time. They have observed that large changes tend be followed by more large changes in either direction, and so volatility must be predictably high after large changes. This phenomenon of securities' volatility, referred to as clustering, has important implications for security pricing and risk management. Among the most popular techniques currently used to capture the clustering effect and to forecast future volatilityare those belonging to the family of Autoregressive Conditional Heteroskedastic (ARCH) models. The main aim of this paper is to investigate whether such volatility modelling can be used to capture the time variation not only in the total risk of a security return but also its systematic and unsystematic components. Using weekly local stock market data, the time varying beta with the World Index has been estimated via a bivariate GARCH-M model. The GARCH-M parameterization used here is a dynamic specification of the SIM. The hypothesis that this dynamic specification holds cannot be rejected for 11 out of 13 local portfolios. The results provide evidence that both the systematic and the non-systematic counterparts are also changing over time. However, in some markets those risk changes may take place with some delay. This suggests that some of the low correlation coefficients computed for certain stock market returns may not be due to differences in business cycles among those countries, but may be caused by the non-synchronous response to world market developments. This finding should have important implications in many investment decisions such as portfolio selection, market timing and risk hedging.     

Firm Size and Cyclical Variations in Stock Returns

Recent imperfect capital market theories predict the presence of asymmetries in the variation of small and large firms' risk over the economic cycle. Small firms with little collateral should be more strongly affected by tighter credit market conditions in a recession state than large, better collateralized ones. This paper adopts a flexible econometric model to analyze these mplications empirically. Consistent with theory, small firms display the highest degree of asymmetry in their risk across recession and expansion states, which translates into a higher sensitivity of their expected stock returns with respect to variables that measure credit market conditions.     

Book-to-market and size effects: compensations for risks or outcomes of market inefficiencies?

We employ the optimal orthogonal portfolio approach to investigate if the size and book-to-market effects in US data are related to risk factors beside the market risk. This method enables us to estimate the upper limit of the risk premium, due to observed as well as all possible unobserved factors, which can be derived from a linear asset pricing model. As a corollary, it is possible to divide the observed average asset return into three parts: one explained by the market factor, one due to the unobserved factors, and finally the non-risk-based (NRB) component. Our empirical results confirm the existence of latent risk factors, which cannot be captured by the market index. In particular, the size effect is related to some other background risk factors than the market portfolio, but a large part of observed book-to-market effect has a NRB explanation.     

Access to external finance: Theory and evidence on the impact of monetary policy and firm-specific characteristics

This paper examines firms’ access to bank and market finance when allowance is made for differences in firm-specific characteristics. A theoretical model determines the characteristics such as size, risk and debt that would determine firms’ access to bank or market finance; these characteristics can result in greater (or lesser) tightening of credit when interest rates increase. An empirical evaluation of the predictions of the model is conducted on a large panel of UK manufacturing firms. We confirm that small, young and risky firms are more significantly affected by tight monetary conditions than large, old and secure firms.     

Book–to–Market Equity, Distress Risk, and Stock Returns

This paper examines the relationship between book–to–market equity, distress risk, and stock returns. Among firms with the highest distress risk as proxied by Ohlson's (1980) O–score, the difference in returns between high and low book–to–market securities is more than twice as large as that in other firms. This large return differential cannot be explained by the three–factor model or by differences in economic fundamentals. Consistent with mispricing arguments, firms with high distress risk exhibit the largest return reversals around earnings announcements, and the book–to–market effect is largest in small firms with low analyst coverage.     

Credit Derivatives and the Default Risk of Large Complex Financial Institutions

This paper proposes and implements a multivariate model of the coevolution of the first and second moments of two broad credit default swap indices and the equity prices of sixteen large complex financial institutions. We use this empirical model to build a bank default risk model, in the vein of the classic Merton-type, which utilises a multi-equation framework to model forward-looking measures of market and credit risk using the credit default swap (CDS) index market as a measure of the conditions of the global credit environment. In the first step, we estimate the dynamic correlations and volatilities describing the evolution of the CDS indices and the banks’ equity prices and then impute the implied assets and their volatilities conditional on the evolution and volatility of equity. In the second step, we show that there is a substantial ‘asset shortfall’ and that substantial capital injections and/or asset insurance are required to restore the stability of our sample institutions to an acceptable level following large shocks to the aggregate level of credit risk in financial markets.     

Credit variance risk premiums

This paper studies variance risk premiums in the credit market using a novel data set of swaptions quotes on the CDX North America Investment Grade and High-Yield indices. The returns of credit variance swaps are negative and economically large, irrespective of the credit rating class. They are robust to transaction costs and cannot be explained by established risk factors and structural model variables. We also dissect the overall variance risk premium into receiver and payer variance risk premiums. We show that credit variance risk premiums are mainly driven by the payer corridor, which is associated with worsening macroeconomic conditions.     

Asset pricing with heterogeneous beliefs

This paper studies the dynamic behavior of security prices in the presence of investors’ heterogeneous beliefs. We provide a tractable continuous-time pure-exchange model and highlight the mechanism through which investors’ differences of opinion enter into security prices. In the determination of equilibrium, we employ a representative investor with stochastic weights and solve for all economic quantities in closed form, including the perceived market prices of risk and interest rate. The basic analysis is generalized to incorporate multiple sources of risk, disagreement about nonfundamentals, and multiple investors. Other applications involving multiple goods and nominal asset pricing within monetary economies are discussed.     

The usefulness of inaccurate models: Towards an understanding of the emergence of financial risk management

Is the growth of modern financial risk management a result of the accuracy and reliability of risk models? This paper argues that the remarkable success of today’s financial risk management methods should be attributed primarily to their communicative and organizational usefulness and less to the accuracy of the results they produced. This paper traces the intertwined historical paths of financial risk management and financial derivatives markets. Spanning from the late 1960s to the early 1990s, the paper analyses the social, political and organizational factors that underpinned the exponential success of one of today’s leading risk management methodologies, the applications based on the Black–Scholes–Merton options pricing model. Using primary documents and interviews, the paper shows how financial risk management became part of central market practices and gained reputation among the different organisational market participants (trading firms, the options clearinghouse and the securities regulator). Ultimately, the events in the aftermath of the market crash of October 1987 showed that the practical usefulness of financial risk management methods overshadowed the fact that when financial risk management was critically needed the risk model was inaccurate.     

Understanding Housing Market Volatility

The Campbell–Shiller present value formula implies a factor structure for the price–rent ratio of housing market. Using a dynamic factor model, we decompose the price–rent ratios of 23 major housing markets into a national factor and independent local factors, and we link these factors to the economic fundamentals of the housing markets. We find that a large fraction of housing market volatility is local and that the national factor has become more important than local factors in driving housing market volatility since 1999, consistent with the findings in Del Negro and Otrok (2007). The local volatilities mostly are due to time variations of idiosyncratic housing market risk premia, not local growth. At the aggregate level, the growth and interest rate factors jointly account for less than half of the total variation in the price–rent ratio. The rest is due to the aggregate housing market risk premium and a pricing error. We find evidence that the pricing error is related to money illusion, especially at the onset of the recent housing market bubble. The rapid rise in housing prices prior to the 2008 financial crisis was accompanied by both a large increase in the pricing error and a large decrease in the housing market risk premium.     

Product market competition and credit risk

This study theoretically and empirically investigates effects of product market competition on credit risk. We first develop a real-options-based structural model in a homogeneous oligopoly and show that credit spreads are positively related to the number of firms in an industry. The disparity of firm size in an industry is relevant to both product market competition and credit risk, and we therefore extend the model to an asymmetric duopoly case. In particular, we demonstrate that credit spreads of relatively small (large) firms within an industry are positively (negatively) related to Herfindahl-Hirschman index, and the relative firm size in an industry is an important determinant of credit risk. The models’ implications are empirically scrutinized by a reduced-form hazard model and generally supported. By performing out-of-sample analyses, the results demonstrate that firm size together with the interaction terms between intra-industry firm size dummies and competition intensity can effectively predict default.     

我国开放式基金绩效及选股和择时能力研究

近年来,开放式基金逐渐成为我国基金市场的绝对主体。开放式基金能否取得较好的绩效受到市场的普遍关注。本文选取了资金管理规模前20位的公司,并从中随机挑选1只基金,运用詹森指数、特雷诺比率、夏普指数和信息比率等单因素模型和Fama-French三因素模型对开放式基金的绩效进行分析,并使用T-M模型、H-M模型、C-L模型对基金经理人股票选股与择时能力进行分析。结果发现:第一,我国开放式基金经理的选股能力存在时变性,在上升期具备选股能力,在下跌期不具备选股能力,而无论是在上升期还是下跌期,基金经理普遍不具备择时能力。第二,在市场上升期基金经理比较注意对风险的把控,系统性风险较小,而在下跌期基金投资组合的系统性风险明显上升,基金经理冒险意愿上升,当市场出现大幅度下跌时,其不理性行为会加剧市场的波动。本文的研究结论有利于提升投资者的风险意识和理性意识、促进外部监管部门的精准监管审查,并能够激励基金经理人提高自身风险管控的能力。     

The effect of capital adequacy guidelines on large bank holding companies

The United States federal bank regulators imposed numerical capital guidelines in 1981. If these guidelines are binding on bank holding companies, then theoretical evidence suggests that banking organizations may be increasing asset risk. This study tests empirically the hypothesis that the guidelines are binding. Two models of changes in bank holding company equity capital to assets ratios are developed and tested using maximum likehood estimation: a regulatory model and a market model. The results indicate that most large bank holding companies are influenced by regulatory forces.     

Local risk factors in emerging markets: Are they separately priced?

We provide new evidence on the pricing of local risk factors in emerging stock markets. We investigate whether there is a significant local currency premium together with a domestic market risk premium in equity returns within a partial integration asset pricing model. Given previous evidence on currency risk, we conduct empirical tests in a conditional setting with time-varying prices of risk. Our main results support the hypothesis of a significant exchange risk premium related to the local currency risk. Exchange rate and domestic market risks are priced separately for our sample of seven emerging markets. The empirical evidence also suggests that although statistically significant, local currency risk is on average smaller than domestic market risk but it increases substantially during crises periods, when it can be almost as large as market risk. Disentangling these two factors is thus important in tests of international asset pricing for emerging markets.     

Firm size and volatility analysis in the Spanish stock market

Using Spanish stock market data, this paper examines volatility spillovers between large and small firms and their impact on expected returns. By using a conditional capital asset pricing model (CAPM) with an asymmetric multivariate GARCH-M covariance structure, it is shown that there exist bidirectional volatility spillovers between both types of companies, especially after bad news. After estimating the model, a positive and significant price of risk is obtained. This result is consistent with the volatility feedback effect, one of the most popular explanations of the asymmetric volatility phenomenon, and explains why risk premiums are much more sensitive to negative return shocks coming from the whole market or other related markets.