货币政策、流动性溢价与股票市场波动

国内外大量研究表明货币政策与股票市场的波动有着千丝万缕的联系。本文基于固浮利差对货币政策进行了分解,采用事件研究法,分析了货币政策对股票市场波动的影响,并探索了货币政策对股票市场波动影响的传导途径。实证结果表明:第一,货币政策对股票市场波动率有负向的影响;第二,未预期的货币政策对股票市场收益率的变化有显著的负向影响;第三,未预期的货币政策对流动性资产的流动性溢价有显著正向影响;第四,准备金和政府债券的流动性溢价在未预期的货币政策对股票市场收益率的影响关系中具有中介效应。     

Understanding Delta-Hedged Option Returns in Stochastic Volatility Environments

In this paper, we provide a novel representation of delta-hedged option returns in a stochastic volatility environment. The representation of delta-hedged option returns provided in this paper consists of two terms: volatility risk premium and parameter estimation risk. In an empirical analysis, we examine delta-hedged option returns based on the result of a historical simulation with the USD-JPY currency option market data from October 2003 to June 2010. We find that the delta-hedged option returns for OTM put options are strongly affected by parameter estimation risk as well as the volatility risk premium, especially in the post-Lehman shock period.     

Ex Ante Stock Market Return Volatility Implied by the OEX Option Premium

Previous empirical evidence suggests that stock return volatility expectations change over time, but the existing models of time-varying variance lack a theoretical structure that is rigorously linked to the efficient markets dividend discount model. This paper develops and tests such a model. The conditional forecast variance of the return on the stock market portfolio is expressed as a linear combination of the adjusted conditional forecast variance of the interest rate and the dividend growth rate. An empirical test using the implied variance of the S&P 100 index option provides evidence that supports the model's predictions.     

Volatility Risk Premium,Risk Aversion,and the Cross‐Section of Stock Returns

We test if innovations in investor risk aversion are a priced factor in the stock market. Using 25 portfolios sorted on book‐to‐market and size as test assets, our new factor together with the market factor explains 64% of the variation in average returns compared to 60% for the Fama‐French model. The new factor is generally significant with an estimated risk premium close to its time series mean also when industry portfolios and portfolios sorted on previous returns are augmented to the test assets.     

中国股票市场风险溢价研究

本文通过综合资产定价理论和实证文献研究结论,对1997年到2009年中国股市A股股票的风险溢价的截面差异作了详尽的实证研究。我们构造25个投资组合作为检验资产,进行Fama-MacBeth两步回归法,建立了基于市场风险溢价,账面市值比,盈利股价比,现金流股价比,投资资本比,工业增加值变化率以及回购利率和期限利差的八因素模型。我们的主要发现有以下三点:一是相对于Fama-French三因素模型,我们模型的实证解释力有显著提高;二是与过去的文献不同,我们发现回购利率和期限利差等债市指标对股市风险溢价的截面数据有显著解释能力;三是与基于投资的资产定价理论一致,我们发现投资比率和现金流股价比能显著反映我国股市的风险溢价。     

Time Varying Market Leverage, the Market Risk Premium and the Cost of Capital

This paper shows that, when as usual the market portfolio is proxied by a share portfolio, then the conventional Ibbotson (1999) estimator of the market risk premium violates Miller–Modigliani (1958 and 1963) propositions II and III. A new estimator of the market risk premium is proposed which is free of these defects. In addition, across the range of market leverages experienced in the US in the period 1952–1997, it generates estimates of the market risk premium that differ from those generated by the Ibbotson methodology by up to 2.5 percentage points, and weighted average costs of capital for firms that differ by up to 2.6 percentage points.     

The Value Premium and Time-Varying Volatility

Abstract:  Numerous studies have documented the failure of the static and conditional capital asset pricing models to explain the difference in returns between value and growth stocks. This paper examines the post-1963 value premium by employing a model that captures the time-varying total risk of the value-minus-growth portfolios. Our results show that the time-series of value premia is strongly and positively correlated with its volatility. This conclusion is robust to the criterion used to sort stocks into value and growth portfolios and to the country under review (the US and the UK). Our paper is consistent with evidence on the possible role of idiosyncratic risk in explaining equity returns, and also with a separate strand of literature concerning the relative lack of reversibility of value firms' investment decisions.     

The Equity Market Risk Premium and the Valuation of Overseas Investments

There is little agreement among academics or practitioners about how to measure the size of the equity market risk premium, particularly when it relates to investments in emerging markets. Using monthly equity returns for 22 developed and 24 emerging markets covering the period 1976–2006, the authors find that developed capital markets have experienced significant increases in their degree of integration with the U.S. and world market indexes, while emerging markets remain at least partly segmented from those of the U.S. and the world. For countries that are reasonably well integrated into global capital markets, the authors suggest using the U.S.—based equity market risk premium. But when valuing investments in emerging markets, they recommend use of the Capital Asset Pricing Model adjusted for political risk and a measure of co‐movement between the foreign and U.S. stock markets. The authors also remind readers that the equity market risk premium is supposed to be a forward‐looking measure, and that the common practice of inferring the future from the past can be misleading, particularly in the case of rapidly developing emerging markets.     

Time-Varying Variance Risk Premium and the Predictability of Chinese Stock Market Return

A number of studies have shown that the variance risk premium (VRP), defined as the difference between risk-neutral and physical expected variances, has strong predictive power for the excess stock market return, and this predictability peaks at 3- to 6-month prediction horizons. However, little research presents empirical evidences for Chinese stock market due to the absence of option market. Under general equilibrium asset pricing framework, this article estimates time-varying VRP using the Chinese stock market data. We find that the estimated VRP predicts the excess Chinese stock market return, and this forecasting power is stronger at 4- and 5-month horizons, which is consistent with the findings of existing literature.     

中国股票市场流动性风险溢价研究

本文在对Fama三因素模型和LACAPM模型进行改进的基础上,实证研究了中国股票市场的流动性风险溢价、规模效应以及价值效应。实证结果发现,改进的FAMA三因素模型能够比CAPM更好地解释价值效应,但却不能解释规模效应和流动性风险溢价现象;而改进的LACAPM在解释市场异象上的有效性则明显优于其他定价模型。     

基于有效波动率的市场一般性风险测度研究

鲁棒跳跃的波动率估计是波动率研究的新方向。本文首先采用蒙特卡洛模拟技术检验鲁棒跳跃波动率估计量MedRV的有效性以及预测的准确性,结果表明:MedRV能够有效鲁棒跳跃行为,得到有效波动率(EV)的估计量,同时相对于双幂次变差(BV)有更好的预测准确性。然后基于MedRV估计量构造了市场一般性风险测度,并对中国证券市场一般性风险分布特征进行了研究,结果表明:基于MedRV估计量所得到的MedRV-VaR指标可以有效摒除极端市场风险因子,得到市场一般性风险测度。     

Do Newly Listed Derivatives Affect the Market Risk Premium in a Thin Stock Market?

This study examines the effects on the stock market unitary risk premium and volatility associated with the listing of stock and stock index derivatives in Switzerland. Based on a univariate GARCH (1,1) specification of the stock index variance and a time-varying unitary risk premium representation, we can reject the hypothesis that stock and stock index derivatives listings do not affect the total risk premium. Contrarily to previous empirical evidence, we find that derivatives listings affect both the conditional market returns' variance and the unitary risk premium through structural shocks. The gradual market completion hypothesis is further corroborated in that, cumulatively, the three stock and stock index options futures derivatives listings reduced the unitary risk premium while the marginal impact of each successive listing decayed.     

波动率风险及风险价格——来自中国A股市场的证据

本文应用Fama-Macbeth估计方法,以1997年2月至2009年6月中国A股股票为样本,考察股票市场波动率风险及其风险价格的特征。研究表明:波动率风险是一个显著的横截面定价因子,其风险价格为负,该结论不受流动性及市场偏度因子、待检资产改变、波动率模型设定的影响;在资产定价模型中引入波动率风险因子有利于解释规模效应和账面市值比效应异象。波动率的风险因子可以涵盖部分宏观经济变量的定价信息,规模因子是波动率风险因子的代理变量。     

Resolving the Puzzling Intertemporal Relation between the Market Risk Premium and Conditional Market Variance: A Two-Factor Approach

The existing empirical literature fails to agree on the nature of the intertemporal relation between risk and return. This paper attempts to resolve the issue by estimating a conditional two-factor model motivated by Merton's intertemporal capital asset pricing model. When long-term government bond returns are included as a second factor, the partial relation between the market risk premium and conditional market variance is found to be positive and significant. The paper also helps explain the convoluted empirical relation between the market risk premium, conditional market variance, and the nominal risk-free rate previously reported in the literature.     

Asian Pacific Stock Market Volatility Modeling and Value at Risk Analysis

The potential for stock market growth in Asian Pacific countries has attracted foreign investors. However, higher growth rates come with higher risk. We apply value at risk (VaR) analysis to measure and analyze stock market index risks in Asian Pacific countries, exposing and detailing both the unique risks and system risks embedded in those markets. To implement the VaR measure, it is necessary to perform "volatility modeling" by mixture switch, exponentially weighted moving average (EWMA), or generalized autoregressive conditional heteroskedasticity (GARCH) models. After estimating the volatility parameters, we can calibrate the VaR values of individual and system risks. Empirically, we find that, on average, Indonesia and Korea exhibit the highest VaRs and VaR sensitivity, and currently, Australia exhibits relatively low values. Taiwan is liable to be in high-state volatility. In addition, the Kupiec test indicates that the mixture switch VaR is superior to delta normal VaR; the quadratic probability score (QPS) shows that the EWMA is inclined to underestimate the VaR for a single series, and GARCH shows no difference from GARCH t and GARCH generalized error distribution (GED) for a multivariate VaR estimate with more assets.     

我国证券市场波动风险预警模型研究

通过对我国证券市场波动性进行线性和非线性的分析,证实了我国证券市场具有聚集效应、时变性和持续性等波动性特征。反映出我国证券市场具有明显的ARCH效应,结合动态风险预警方法,应用GARCH类模型构建VaR我国证券市场的风险预警模型。通过检验,证实了该风险预警模型适用我国证券市场波动风险预警。     

Equity Risk Premium

Abstract

The equity risk premium (ERP) is an essential building block of the market value of risk. In theory, the collective action of all investors results in an equilibrium expectation for the return on the market portfolio excess of the risk-free return, the ERP. The ability of the valuation actuary to choose a sensible value for the ERP, whether as a required input to capital asset pricing model valuation, or any of its descendants, is as important as choosing risk-free rates and risk relatives (betas) to the ERP for the asset at hand.

The historical realized ERP for the stock market appears to be at odds with pricing theory parameters for risk aversion. Since 1985, there has been a constant stream of research, each of which reviews theories of estimating market returns, examines historical data periods, or both. Those ERP value estimates vary widely from about ?1% to about 9%, based on a geometric or arithmetic averaging, short or long horizons, short- or long-run expectations, unconditional or conditional distributions, domestic or international data, data periods, and real or nominal returns.

This paper examines the principal strains of the recent research on the ERP and catalogues the empirical values of the ERP implied by that research. In addition, the paper supplies several time series analyses of the standard Ibbotson Associates 1926–2002 ERP data using short Treasuries for the risk-free rate. Recommendations for ERP values to use in common actuarial valuation problems also are offered.     

Market Illiquidity and Conditional Equity Premium

We examine the time‐series relation between aggregate bid‐ask spreads and conditional equity premium. We document that average marketwide relative effective bid‐ask spreads forecast aggregate market returns only when controlling for average idiosyncratic variance. This control allows us to document the otherwise elusive relation between illiquidity and returns. The reason is that idiosyncratic variance correlates positively with spreads but has a negative effect on conditional equity premium, causing an omitted variable bias. Our results are robust to standard return predictors, alternative illiquidity measures, and out‐of‐sample tests. These findings are important because they provide strong support for the literature's conjecture that marketwide liquidity is an important asset pricing risk factor.