A股市场股权风险溢价的历史及启示

本文计算了1992～2000年、2001～2005年以及1992～2005年三个时间窗口下A股市场的股权风险溢价率；基于历史数据，就投资者所要求的股权风险溢价、通货膨胀与股权风险溢价的关系等问题进行了初步分析；相关分析也隐含了A股市场发展的政策建议。     

Estimating the Equity Risk Premium Using Accounting Fundamentals

This study uses recent developments in the theoretical modelling of the links between unrecorded accounting goodwill, accounting profitability and the cost of equity, together with Capital Asset Pricing Model (CAPM) betas, to estimate the ex-ante equity risk premium in the UK. The results suggest that, over our sample period from 1968 to 1995, the premium has been in the region of 5%. Our estimate lends support to the view that the ex-ante equity risk premium is substantially less than the historical average of the excess of equity returns over the risk-free rate, and is similar to the rates applied recently by UK competition regulators.     

折现率中股权风险溢价的确定

折现率中的股权风险溢价一般采用资本资产定价模型来确定,但由于资本资产定价模型建立在投资者理性、股票市场有效等前提基础之上,而中国股票市场的有效性比较欠缺,在评估实践中运用资本定价模型确定股权风险溢价存在较多的问题。本文从实体经济领域着手,通过投入产出分析、经营杠杆及财务杠杆分析,计算出行业相对于整体经济的风险系数、目标企业相对于行业的风险系数,进而得到行业股权风险溢价和目标企业的股权风险溢价。     

The Equity Premium

We estimate the equity premium using dividend and earnings growth rates to measure the expected rate of capital gain. Our estimates for 1951 to 2000, 2.55 percent and 4.32 percent, are much lower than the equity premium produced by the average stock return, 7.43 percent. Our evidence suggests that the high average return for 1951 to 2000 is due to a decline in discount rates that produces a large unexpected capital gain. Our main conclusion is that the average stock return of the last half-century is a lot higher than expected.     

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.     

Estimating the Equity Risk Premium and Expected Equity Rates of Return: The Case of Canada

It is common to use the average excess return of equities over bonds estimated over long time periods as an expected equity risk premium on the grounds that going back far enough covers most possible economic scenarios. But although this data is useful in guiding the exercise of judgment, it cannot substitute for judgment. Adding more years of data to the near century of Canadian stock and bond returns that inform today's estimate of the equity risk premium will not produce a “random walk” for a simple reason: the historic bond series is the result of a specific historic monetary policy. This is particularly true of and important for the case of Canada, where today's very low current bond yields reflect the emergence of the Canadian dollar as a reserve currency as well as the impact of unconventional monetary policy elsewhere. After analyzing the historic record of the Canadian equity risk premium and noting the need for adjustments when this premium is applied to the current anomalously low Canadian long‐term bond yields, the author reaches the following conclusions:

• The historic Canadian equity risk premium is approximately 5.0% (based on arithmetic returns), which is slightly lower than the roughly 6.0% value for the U.S.
• The historic equity risk premium has not been constant because of obvious changes in the Canadian bond market. To some extent, the huge cycle in which bond yields began their increase from the 4.0% level starting in 1957, when markets were liberalized, and then fell back to the 4.0% level in 2007‐2008 completed an adjustment to changes in fiscal versus monetary policy. However, in 2016, average long Canada bond yields dropped to an anomalously low 1.8%, which is below the long‐term inflation target of the Bank of Canada, and have barely recovered since. It is difficult to view this as an equilibrium rate determined by private investors.
• Of the drop in bond yields, about 0.50% is unique to Government of Canada bonds as they became attractive to sovereign investors as a rare AAA‐rated issuer.
• Using an indicator variable for the post‐2010 years, a simple regression analysis indicates that current long Canada bond yields should be about 2.75% higher but for the recent changes. And for 2018, this means that the 2.35% average long Canada bond yield should have been about 5.0%. Apart from the impact of higher government deficits, this is consistent with average yields before the 2008 financial crisis.
• Adding an adjusted 5.0% long Canada bond yield to the historic equity risk premium in Canada of 4.50% gives 9.50% for the cost of the overall equity market or, given the Bank of Canada's target inflation rate of 2.0%, a real equity return of 7.5%, both slightly higher than the long‐run averages.

In sum, the conventional practice of adding a historic market risk premium to the current low Canada long bond yields would impart a sharp downward bias to current equity cost estimates; use of this method would not be appropriate until long Canada bond yields increase to at least the 4.0% level.     

Age‐Dependent Increasing Risk Aversion and the Equity Premium Puzzle

We introduce a new preference structure—age‐dependent increasing risk aversion (IRA)—in a three‐period overlapping generations model with borrowing constraints, and examine the behavior of equity premium in this framework. We find that IRA preferences generate results that are more consistent with U.S. data for the equity premium, level of savings and portfolio shares, without assuming unreasonable levels of risk aversion. We find that the relative difference between the two risk aversions (how much more risk‐averse old agents are relative to the middle‐aged) matters more than the average risk aversion in the economy (how much more risk‐averse both cohorts are). Our findings are robust with respect to a number of model generalizations.     

The Equity Premium and Structural Breaks

A long return history is useful in estimating the current equity premium even if the historical distribution has experienced structural breaks. The long series helps not only if the timing of breaks is uncertain but also if one believes that large shifts in the premium are unlikely or that the premium is associated, in part, with volatility. Our framework incorporates these features along with a belief that prices are likely to move opposite to contemporaneous shifts in the premium. The estimated premium since 1834 fluctuates between 4 and 6 percent and exhibits its sharpest drop in the last decade.     

Accruals and the Conditional Equity Premium

Accruals correlate closely with the determinants of the conditional equity premium at both the firm and the aggregate levels. The common component of firm‐level accruals, which cannot be diversified away by aggregation, explains the positive relation between aggregate accruals and future stock market returns. The residual component, which accounts for most variation in firm‐level accruals, is responsible for the negative cross‐sectional relation between firm‐level accruals and future stock returns. Consistent with the risk‐based explanation, aggregate accruals, as a proxy for the conditional equity premium, forecast changes in aggregate economic activity. Moreover, we document a similar comovement of earnings with the conditional equity premium at both the firm and the aggregate levels, which helps explain the negative relation between changes in aggregate earnings and contemporaneous market returns.     

Luxury Goods and the Equity Premium

This paper evaluates the equity premium using novel data on the consumption of luxury goods. Specifying utility as a nonhomothetic function of both luxury and basic consumption goods, we derive pricing equations and evaluate the risk of holding equity. Household survey and national accounts data mostly reflect basic consumption, and therefore overstate the risk aversion necessary to match the observed equity premium. The risk aversion implied by the consumption of luxury goods is more than an order of magnitude less than that implied by national accounts data. For the very rich, the equity premium is much less of a puzzle.     

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.     

国债期限溢价与股权溢价之间动态相关性分析

鉴于国债期限溢价与股权溢价之间的相关关系具有时变性特征,本文运用BEKK-MGARCH、ADCC-MGARCH等模型从条件相关系数角度考察国债期限溢价与股权溢价之间的动态相关性。经验分析结果发现,在描述两者的相关性动态变化方面,考虑非对称性的ADCC-MGARCH模型优于BEKK-MGARCH模型;尽管国债期限溢价与股权溢价之间的条件相关系数大小在短期内会发生变动,但是条件相关系数在正负符号上却保持相对稳定。     

Survival Bias and the Equity Premium Puzzle

Previous authors have raised the concern that there could be serious survival bias in the observed U.S. equity premium. Contrary to conventional wisdom, we argue that the survival bias in the U.S. data is unlikely to be significant. To reach this conclusion, we introduce a general framework for modeling survival and derive a mathematical relationship between the ex ante survival probability and the average survival bias. This relationship reveals the fundamental difficulty facing the survival argument: High survival bias requires an ex ante probability of market failure, which seems unrealistically high given the history of world financial markets.     

Conditional Equity Premium and Aggregate Corporate Investment

We document a strong negative relation between aggregate corporate investment and conditional equity premium estimated from direct stock market risk measures. Consistent with the investment-based asset pricing model, the comovement with conditional equity premium fully accounts for aggregate investment's market return predictive power. Similarly, conditional equity premium is a significant determinant of classic Tobin's q measure, although q has much weaker explanatory power for aggregate investment possibly because of its measurement errors. Moreover, the positive relation between aggregate investment and investor sentiment documented in previous studies reflects the fact that both variables correlate closely with conditional equity premium.     

Non-addictive Habit Formation and the Equity Premium Puzzle

I analyse a model in a simple representative-agent economy with one risky and one riskless asset, populated by habit forming consumer-investors. These consumer-investors exhibit non-addictive habit formation in the sense that the current consumption rate of the consumer-investors can fall below their past habit-forming consumption rate. I endogenise the real riskless rate of return in this representative-agent economy and find that the equity premium puzzle is resolved for plausible values of the coefficient of relative risk aversion, the discount rate, and the intensity of non-addictive habit formation. These values have been validated in previous empirical or survey-based studies. Non-addictive habit-formation studied here complements and extends current research on habit-forming preferences. Given a constant investment opportunity set, the real riskless rate in the economy increases with relative risk aversion of the consumer and decreases as the habit-formation intensity increases. Extensions with time-varying investment opportunity sets could explain the low risk-free rate and the relatively large variability of the market return over the variability of the risk-free rate through time.     

The Globalization Risk Premium

In this paper, we investigate how globalization is reflected in asset prices. We use shipping costs to measure firms' exposure to globalization. Firms in low shipping cost industries carry a 7% risk premium, suggesting that their cash flows covary negatively with investors' marginal utility. We find that the premium emanates from the risk of displacement of least efficient firms triggered by import competition. These findings suggest that foreign productivity shocks are associated with times when consumption is dear for investors. We discuss conditions under which a standard model of trade with asset prices can rationalize this puzzle.     

社会变迁、风险规避与股权溢价之谜——来自晚清、民国与当代中国股票市场的经验证据

本文在收集和整理近百年中国股市、居民消费、人均GDP、物价指数和利率的数据的基础上,利用近代和现代中国的数据检验中国是否存在“股权溢价之谜”。研究发现:1888-1938年的近代股市投资者的风险规避系数在较为合理的范围之内。而中国当代股市和1939-1947年近代股市投资者的风险规避系数均大于一般合理的水平,即都存在“股权溢价之谜”,而且1939-1947年股市投资者的风险规避程度要大大高于当代股市投资者。本文分析认为,以全国战争和恶性通货膨胀为主要表现的社会动荡加大了近代股票投资的“背景风险”,从而使得这一时段投资者的风险规避程度和股权溢价都大幅增加。     

中国股市股权溢价的实证研究

在经济理论中,股权溢价是有一定的合理范围的,当实际溢价超过理论最大值时,就会产生无法解释的谜.本文运用中国股市的实际收益率数据,使用广义矩法(GMM),来估计相对风险厌恶系数和时间偏好系数,看是否在理论允许的合理范围之内.并利用中国股市1991-2007年的完整样本与样本分割相结合,对比不同时间段的股权溢价状况和估计的参数进行实证研究.结果表明,中国的股权溢价仍然在合理范围之内,但是各样本期变动很大.     

Heterogeneous Beliefs, Speculation, and the Equity Premium

Agents with heterogeneous beliefs about fundamental growth do not share risks perfectly but instead speculate with each other on the relative accuracy of their models' predictions. They face the risk that market prices move more in line with the trading models of competing agents than with their own. Less risk‐averse agents speculate more aggressively and demand higher risk premiums. My calibrated model generates countercyclical consumption volatility, earnings forecast dispersion, and cross‐sectional consumption dispersion. With a risk aversion coefficient less than one, agents' speculation causes half the observed equity premium and lowers the riskless rate by about 1%.     

The UK Equity Premium: 1901–2004

Abstract:  This paper examines the UK equity premium over more than a century using dividend growth to estimate expectations of capital gains employing the approach of Fama and French (2002) . Over recent decades estimated equity premia implied by dividend growth have been much lower than that produced by average stock returns for the UK market as a whole; a finding corroborated by all economic sub-sectors. The empirical analysis suggests this is primarily due to a declining discount rate, during the latter part of the 20th century, which would rationally stimulate unanticipated equity price rises during this period. Thus, I conclude that historical stock returns over recent decades have been above investors' expectations.