资本资产定价理论与市场经济

资本资产定价模型(CAPM)是威廉·夏普于1964年在马克威茨的资产组合理论和托宾分离定理的基础上通过增加一些条件而建立起来的资本市场均衡定价模型。在CAPM的假设前提下,资本市场被带入一种所有的投资者持有相同风险资产市场组合的均衡状态,在这种状态下经济中所有的风险资产特别是企业资产都具有完全相同的所有权结构。从而将经济带入一种所有企业之间不存在利益冲突的"准公有制"状态,市场经济制度也将不复存在。如果我们认为这一结论是荒谬的,那问题一定出在CAPM的假设条件以及由此假设条件所推出的市场均衡,自然,建立在这种均衡状态下的资本资产定价模型的现实性也是成问题的。     

CAPM and the changing distribution of historical returns

Three statistical tests reject the capital asset pricing model (CAPM) assumption of a constant distribution of returns over time, for three different aggregate stock indices over various holding periods since 1950. These findings further undermine the reliability of CAPM applied to historical data for choosing optimal portfolio allocations.     

Which is the best: A comparison of asset pricing factor models in Chinese mutual fund industry

Factor models are commonly used in estimating risk-adjusted fund performance. We compare the commonly used factor models in empirical asset pricing studies and find that Fama and French (2015) five-factor model outperforms other models in the Chinese mutual fund industry and in most fund segments. The factor models we tested are more effective in explaining the return of index funds than other types. Meanwhile, we also find that the capital asset pricing model (CAPM) better controls the estimated alpha dispersion than other models. Though most multifactor models including Carhart (1997) have higher R-squared than CAPM, the cross-sectional differences between them are not statistically significant.     

The evolution of portfolio rules and the capital asset pricing model

The aim of this paper is to test the performance of capital asset pricing model (CAPM) in an evolutionary framework. We model an economy where a heterogeneous population of long-lived agents invest their wealth according to different portfolio rules, and prove that traders who either “believe” in CAPM and use it as a rule of thumb, or are endowed with genuine mean-variance preferences, under some very weak conditions, vanish in the long run.We show that a sufficient condition to drive CAPM or mean-variance traders’ wealth shares to zero is that an investor endowed with a logarithmic utility function enters the market.     

Liquidity-adjusted conditional capital asset pricing model

This paper derives a liquidity-adjusted conditional two-moment capital asset pricing model (CAPM) and a liquidity-adjusted conditional three-moment CAPM respectively based on theory of stochastic discount factor. The liquidity-adjusted conditional two-moment CAPM shows that a security's conditional expected excess return consists of three parts: its conditional expected liquidity cost, the systemic risk premium and the liquidity risk premium. The liquidity-adjusted conditional three-moment CAPM shows that a security's conditional expected excess return depends on its conditional expected liquidity cost, the conditional covariance between its return and the market return, the conditional covariance between its liquidity cost and the market liquidity cost, and the conditional coskewness of its return and the market return.     

THE DISTRIBUTION OF BETAS IN PRESENCE OF NONTRADED ASSETS

This study considers a capital assets pricing model (CAPM) in an incomplete financial market wherein not all risky assets are traded and the risk from non‐traded assets is not orthogonal to that of the existing or traded assets. The model shows the extent of the divergence of the CAPM betas (true betas) from the traditional CAPM betas (perceived betas) in market equilibrium conditions in an incomplete market. Specifically, it implies that the more incomplete a financial market is, the wider is the discrepancy between the true and perceived betas, and the distribution of the perceived betas tends to centre more around 1 in an incomplete market than that of true betas. Empirical evidence in various settings support these results.     

A portfolio approach to climate investments: CAPM and endogenous risk

Is there a role for investments in climate change mitigation despite low expected return? We use a model of intertemporal expected utility maximisation to analyse this question. Similar to the capital asset pricing model (CAPM) the rate of return depends on the correlation of risk between the return on investments in climate change mitigation and the market portfolio, but in contrast to the classical CAPM we admit the fact that economic and environmental systems are jointly determined, implying that environmental risk is endogenous. Therefore, investments in climate change mitigation may reduce risk via self-protection and self-insurance. If risk reduction is accounted for in cost–benefit evaluations, climate investments may be justified despite low expected return. These aspects of climate investments are not, however, communicated via standard cost–benefit analyses of climate policy. Optimal climate policy may therefore be more ambitious than previously considered.     

A capital adequacy buffer model

We develop a new capital adequacy buffer model (CABM) that is sensitive to dynamic economic circumstances. The model, which measures additional bank capital required to compensate for fluctuating credit risk, is a novel combination of the Merton structural model, which measures distance to default and the timeless capital asset pricing model (CAPM), which measures additional returns to compensate for additional share price risk. We apply the model to a portfolio of mid-cap loan assets over a 10-year period that includes pre-GFC (global financial crisis), GFC and post-GFC. An analysis of actual defaults over this period shows the model to be far more accurate in determining the capital adequacy levels needed to counter credit risk than an unresponsive ratings model such as the Basel standardized approach.     

Capital asset pricing model in Portugal: Evidence from fractal regressions

We examine risk profiles of the Portuguese stock market index component stocks using a novel approach to the classical capital asset pricing model (CAPM). Specifically, we estimate the CAPM via fractal regressions that allow studying the marginal effects at selected scales. In this way, we can reveal whether the risk is perceived differently by market participants with different investment horizons. Apart from the analysis itself, we provide new statistical insights into the issue of separating and comparing the scale-specific effects with statistical validity. We find several stocks deviating from an expected risk perception homogeneity across investment horizons. This is true for both analysed periods, i.e. before and after the global financial crisis. There are also several stocks that changed their relationship to the market portfolio in between, which has strong implications for possible portfolio construction. The proposed methodology is not limited to financial topics but can be used in any discipline where the scale-specific marginal effects might be of interest.     

Drivers of expected returns in Istanbul stock exchange: Fama–French factors and coskewness

We investigate the impact of coskewness on the variation of portfolio excess returns in Istanbul Stock Exchange (ISE) over the period July 1999 to December 2005. We form portfolios according to size, industry, size and book-to-market ratio, momentum and coskewness and compare alternative asset pricing models. The traditional capital asset pricing model (CAPM) and the three-factor model of Fama and French are tested in the multivariate testing procedure of Gibbons–Ross–Shanken (1989). Coskewness is introduced as a fourth factor and its incremental effect over CAPM and Fama–French factors is examined both in multivariate tests and in cross-sectional regressions. The findings reveal that coskewness is able to explain the size premium in ISE. Hence, the basic two-moment CAPM without the coskewness factor would underestimate the expected return of size portfolios. Multivariate test results indicate that coskewness reduces the pricing bias, albeit insignificantly. Cross-sectional analysis uncovers that coskewness has a significant additional explanatory power over CAPM, especially for size and industry portfolios. However, coskewness does not have a significant incremental explanatory power over Fama–French factors in ISE.     

可交易价值与股票短期收益分析——基于不同市场环境的实证研究

通过对股票可交易过程的分析,提出可交易价值的概念并指出价格、流动性和波动性是构成可交易价值的主要因素,并在CAPM模型的基础上建立考虑股票可交易价值的资本资产定价模型。运用横截面回归法分别对我国沪深A股市场处于熊市和牛市阶段的行业日交易数据进行实证分析,指出以日风险收益率为代表的股票短期预期收益率不仅与传统系统风险因子有关,还受可交易价值中价格因子、流动性因子和波动性因子影响。并且,在不同市场环境下,可交易价值各因子的表现形式也不同,既反映出市场及投资者不同的心理预期,也为市场预测和监管提供了一种新的途径。     

An examination of the economic significance of stock return predictability in UK stock returns

We explore the out-of-sample performance of domestic UK asset allocation strategies that use forecasts of expected returns from a linear predictive regression and those that are implied by asset pricing models such as the capital asset pricing model (CAPM) or arbitrage pricing theory (APT). Our findings suggest that using forecasts of expected returns from the predictive regression generate significant benefits in out-of-sample performance. We find the performance of the strategies using expected return forecasts implied by the CAPM or APT is lower than the predictive regression strategy. However, with binding investment constraints, the performance of the APT matches that of the predictive regression.     

Asset pricing theory and the valuation of Canadian paintings

Abstract.  The valuation of Canadian paintings is analysed empirically. Using a sample of auction prices for major Canadian painters for the period 1968–2001, we run hedonic regressions to analyse the influence of various factors, including painter identity, on auction prices, as well as to construct a market price index. This index is used in a second‐stage analysis in which we analyse the properties of Canadian art viewed as an investment asset. We apply standard asset pricing theory, as incorporated in the capital asset pricing model (CAPM), to the analysis of price movements in the market for Canadian paintings.     

The capital asset pricing model in economic perspective

The capital asset pricing model (CAPM) is theoretically incomplete in its demand-side focus, risk-averse investors and internally inconsistent homogeneous beliefs; is not conclusively supported empirically; and yet it legitimizes a notion that investors can earn higher returns by bearing undiversifiable risk. Our article does not merely extend the CAPM with more realistic assumptions, it completes its original framework by including (1) risk-taking investors in the investor population, (2) investors who can have heterogeneous expectations or beliefs – an overlooked but required condition for the CAPM to be an internally consistent and meaningful model of competitive financial asset pricing under uncertainty and (3) a positive-sloped short-run supply curve based on a reasonable interpretation of the nature of financial asset trade. Upon a complete economic interpretation, it is shown that the equilibrium (systematic) risk-rate of return relationship depends on whose aggregate trading activity dominates, risk-averse or risk-taking investors’. There is no universal, or even general, positive relationship between systematic risk and rate of return. This has far-reaching implications for investors and investment advisors who serve them.     

Rolling Regression Analysis of the Pástor-Stambaugh Model: Evidence from Robust Instrumental Variables

The capital asset pricing model (CAPM), Fama-French (FF), and Pástor-Stambaugh (PS) factor models are examined using a new dynamic rolling regression version of the generalized method of moments (GMM) method. This rolling regression framework not only allows us to investigate phases of the business cycle, but also permits regression estimates to vary through time due to changes in the development and efficiency of the sectors. The principal reasons for using the dynamic GMM with robust instruments is that some of these factors are measured with errors and the disturbances may be non-spherical. The CAPM appears as the most parsimonious model to explain the FF sector returns. Furthermore, the rolling GMM approach is clearly more sensitive to dynamic financial episodes than the ordinary least squares approach. In particular, liquidity has some anticipatory power, as it is able to forecast the 2007–2009 crises with heightened volatility starting in late 2005.     

以MM理论与CAPM模型结合为基础的项目评估研究

当企业进行一个新行业项目投资时,项目的风险有可能高于企业现有的平均风险水平,因此采用什么样的贴现率对新项目进行评估,是企业是否进行该项目投资的一个主要判断。目前对MM理论与CAPM理论的结合研究大都以资本成本公式比较为基础,得到负债经营与未负债经营企业之间风险系数的等式。当我们把企业本身视为资产组合时,企业资产的风险系数应该是权益资本和债务资本风险系数的加权平均,结合MM理论中对负债的风险定义也可以得到该等式。同时,如何把计算出的＂未负债系数＂应用到企业投资评估中有现实意义。     

Variance and lower partial moment betas as bases for costing equity capital among regulated utilities

An important question in the setting of public utility rates is, ‘What constitutes a fair rate of return or cost of equity capital for a regulated utility?’ Recent debates over this issue have centred on the CAPM's ability to produce realistic equity cost figures for use in the rate-setting process. Several researchers recommend modified or expanded versions of the market model as a means of improving its predictive capabilities. One such approach is the lower partial moment model. The purpose of the present paper is to assess the robustness of the lower partial moment model relative to the conventional CAPM as a basis for estimating the cost of a utility company's equity capital. The hypothesis that empirical estimates of the LPM beta tend to overestimate the true systematic risk of utility companies was corroborated by our test results.     

资本市场的实验经济学方法论研究

随着金融市场理论研究和实践检验的不断发展，资本市场的许多基础理论受到了极大的挑战，与现有理论相悖的异象不断涌现。新近兴起的实验经济学为人们研究资本市场提供了一条更为有效的途径。本文分析了实验方法在资本市场研究中的利与弊，介绍了部分资本市场实验的设计过程，并应用该方法分析了风险与收益、资本市场的效率、市场泡沫的产生和破灭、CAPM理论，以及交易制度等。文章指出，在资本市场中运用实验方法进行研究，具有可控性、可比性以及可重复性等优点，为我们对于资本市场诸多理论进行检验提供了可能。在资本市场实验的设计中，我们不但需要考虑实验的各种交易制度，还需要考虑到被试人员的选择、交易资产的确定以及市场信息的设计等很多问题，只有对这些问题进行全面地考虑，才能保证实验结果的可信度，进而为我们对于各种金融理论的检验提供可能。     

信息、投资者行为与资本市场效率

以资本资产定价模型 (CAPM)为代表的新古典派资本市场理论从信息的完全性、市场参加者的完全理性、市场的无摩擦性与风险的可计量性这四个假设前提出发 ,通过主体均衡与市场均衡推导出一系列理想中的资本市场命题。但我们不应忘记 ,现实中的资本市场是远离该理想市场的 ,基于理想市场的事件研究这一实证分析手法也是有很大局限性的。我们应对市场中信息的不完全性、信息的非对称性以及投资者的有限理性等给予足够重视 ,加强对如何提高现实资本市场的资源配置效率的研究     

Time-varying exchange rate exposure and exchange rate risk pricing in the Canadian Equity Market

This paper aims to extend the existing literature on foreign exchange rate risk pricing. Unlike the existing studies on Canada, we use six alternative bilateral and one multilateral exchange rate proxies. Furthermore, using both a two-factor and a three-factor capital asset pricing model (CAPM), we test for the presence of a long-run relationship among exchange rate risk pricing, herding behavior, term structure and the interest rate. The estimated results based on both the ordinary least squares (OLS) and generalized least squares (GLS) estimation techniques confirm that exchange rate risk in the Canadian equity market is priced and that the pricing of this risk is time-varying. This result holds for all seven exchange rate proxies. Our empirical analysis also suggests the presence of a long-run relationship among exchange rate risk pricing, herding behavior, term structure and the interest rate. This relationship is found to be insensitive to variations in the world market return.