Option-Implied Risk Aversion Estimates

Using a utility function to adjust the risk‐neutral PDF embedded in cross sections of options, we obtain measures of the risk aversion implied in option prices. Using FTSE 100 and S&P 500 options, and both power and exponential‐utility functions, we estimate the representative agent's relative risk aversion (RRA) at different horizons. The estimated coefficients of RRA are all reasonable. The RRA estimates are remarkably consistent across utility functions and across markets for given horizons. The degree of RRA declines broadly with the forecast horizon and is lower during periods of high market volatility.     

State Dependence Can Explain the Risk Aversion Puzzle

Risk aversion functions extracted from observed stock and optionprices can be negative, as shown by Aït-Sahalia and Lo(2000), Journal of Econometrics 94: 9–51; and Jackwerth(2000), The Review of Financial Studies 13(2), 433–51.We rationalize this puzzle by a lack of conditioning on latentstate variables. Once properly conditioned, risk aversion functionsand pricing kernels are consistent with economic theory. Todifferentiate between the various theoretical explanations interms of heterogeneity of beliefs or preferences, market sentiment,state-dependent utility, or regimes in fundamentals, we calibrateseveral consumption-based asset pricing models to match theempirical pricing kernel and risk aversion functions at differentdates and over several years.     

How Does Information Quality Affect Stock Returns?

Using a simple dynamic asset pricing model, this paper investigates the relationship between the precision of public information about economic growth and stock market returns. After fully characterizing expected returns and conditional volatility, I show that (i) higher precision of signals tends to increase the risk premium, (ii) when signals are imprecise the equity premium is bounded above independently of investors' risk aversion, (iii) return volatility is U-shaped with respect to investors' risk aversion, and (iv) the relationship between conditional expected returns and conditional variance is ambiguous.     

Relative risk aversion once more: An analysis of Japanese households' financial asset holding pattern

It is widely accepted that as the total assets increse, households tend to diversify their portfolios. In other words, absolute risk aversion is decreasing. On the other hand, the proportion of risky assets may increase or decrease depending on whether relative risk aversion (RRA) is decreasing or increasing, and its direction is still left open as an empirical question. This study examines the constancy of RRA from Japanese individual households' financial asset holding data collected in 1984. Constant RRA implies that the proportion of risky assets in one's portfolio is constant regardless of the amount of total assets. A casual observation of household portfolio holding pattern suggests that this implication is clearly violated by the data, because there are substantial proportion of households which do not hold any risky assets. Zero-holding, however, may be interpreted as a result of fixed transaction cost incurred by individual investors when they hold risky assets. Then, we pose a question, ‘Do investors hold constant proportion of risky assets, when they decide to hold them?’ In order to explain a substantial number of zero risky asset holders in the sample, we propose a portfolio selection model with a transaction cost, and estimate the model using a variant of Heckman's two-step method. In estimation we control for individual investors' socioeconomic characteristics, as well as income and total assets. The construction of the model imposes nonlinear restrictions on the two estimators, from which we can test the specification of the model. The estimation results suggest that there is a statistically significant decreasing tendency linked to total assets but that its rate of change tapers off as total assets increase. Our results are consistent with the previous studies which tended to support constant RRA for the higher asset holders, and complement previous studies in explaining lower asset holders' investment behavior.     

全球投资者国别风险情绪对跨境股票资本流动的影响

本文分析了全球投资者国别风险情绪对跨境股票资本流动的影响,通过构造一般均衡跨期选择模型,刻画了投资者国别风险情绪负向影响跨境股票净资本流入的理论机理以及投资者风险厌恶程度的调节作用,并基于EPFR全球股票型基金微观数据和由大数据文本分析技术构造的全球投资者国别层面风险情绪指标进行实证检验。结果表明:第一,全球投资者对一国的国别风险情绪上升会推升该国的整体风险溢价水平,降低跨境股票型基金净资本流入,尤其是风险厌恶度较高的被动型、开放式和ETF基金;第二,一国金融市场成熟度上升和汇率弹性增强可以缓解全球投资者国别风险情绪对跨境股票型基金净资本流入的负向影响;第三,在全球风险情绪极端低或者各国股票型基金净资本流入极端高的时期,全球投资者国别风险情绪的影响更为显著。     

考虑背景风险的生命周期投资模型评述——兼论居民投资者风险教育

背景风险是指特定居民在生命周期投资过程中承担的市场风险以外的风险。已有的研究文献认为,劳动、职业、健康与房产等背景对居民投资组合会产生影响。不同文献在引入背景风险后均对模型目标函数围绕新的变量做了技术上的不同处理,进而模型背景风险的估计、模型求解方法也产生了相应的差异。对模型结果的解释则陷于市场有效性之争,并无定论。本文最后给出了生命周期投资模型对居民投资者风险教育的启示。     

中国个人投资者处置效应研究——一个非理性信念的视角

处置效应是指投资者过早卖出盈利股票而长期持有亏损股票的现象。大量文献表明金融市场投资者存在显著的处置效应,但其产生的原因和机理存在争议。本文在前景理论框架下,构建了包含投资者非理性预期的离散时间投资组合决策模型,发现处置效应随投资者情绪升高而减弱。本文使用我国某券商2007—2009年近177万个人投资者股票账户的交易数据进行了实证分析,得到与理论模型预测的一致结果,即投资者情绪与投资者处置效应之间呈现显著的负相关关系。而且,受情绪影响,投资者处置效应在估值难度较大的股票中更弱。本文结论对理解投资者处置效应、优化投资者卖出决策和加强资本市场基础制度建设具有一定理论和实践意义。     

Aggregate idiosyncratic volatility,dynamic aspects of loss aversion,and narrow framing

We consider the economy in which an agent faces, in addition to market risk, an additive independent background risk in consumption. In contrast to the Lucas (Econometrica 46:1429–1445, 1978) complete consumption insurance model, under plausible assumptions about the unconditional mean and variance of the agent’s subjective distribution of background risk the model with the additive independent background risk fits the historical average excess return on the US stock market with the coefficient of relative risk aversion (RRA) below five for the subsets of households designated as assetholders. The greater the size and/or the lower the expected value of background risk, the lower (compared to the Lucas (Econometrica 46:1429–1445, 1978) model) the value of the RRA coefficient needed for the model with background risk to match the historical average equity premium. Allowing for an extremely unlike large decrease in the agent’s consumption considerably decreases the required coefficient of RRA. It is concluded that the presence of the additive independent background risk in the consumption of assetholders can account for nearly 60 % of the historical average equity premium, hence rationalizing the equity premium puzzle of Mehra and Prescott (J Monet Econ 15:145–162, 1985). With RRA below five, the model with background risk is consistent with the historical average real interest rate if the agent has the subjective time discount factor lower than, but close to, 1. The findings are robust to the assumed type of background risk, the proxy for the market portfolio, and the threshold value in the definition of assetholders.     

Multifactor models and their consistency with the ICAPM

Can any multifactor model be interpreted as a variant of the Intertemporal CAPM (ICAPM)? The ICAPM places restrictions on time-series and cross-sectional behavior of state variables and factors. If a state variable forecasts positive (negative) changes in investment opportunities in time-series regressions, its innovation should earn a positive (negative) risk price in the cross-sectional test of the respective multifactor model. Second, the market (covariance) price of risk must be economically plausible as an estimate of the coefficient of relative risk aversion (RRA). We apply our ICAPM criteria to eight popular multifactor models and the results show that most models do not satisfy the ICAPM restrictions. Specifically, the “hedging” risk prices have the wrong sign and the estimates of RRA are not economically plausible. Overall, the Fama and French (1993) and Carhart (1997) models perform the best in consistently meeting the ICAPM restrictions. The remaining models, which represent some of the most relevant examples presented in the empirical asset pricing literature, can still empirically explain the size, value, and momentum anomalies, but they are generally inconsistent with the ICAPM.     

Trading volume with private valuation: evidence from the ex-dividend day

We test a theory of the interaction between investors' heterogeneity,risk, transaction costs, and trading volume. We take advantageof the specific nature of trading motives around the distributionof cash dividends, namely the costly trading of tax shields.Consistent with the theory, we show that when trades occur becauseof differential valuation of cash flows, an increase in riskor transaction costs reduces volume. We also show that the nonsystematicrisk plays a significant role in determining the volume of trade.Finally, we demonstrate that trading volume is positively relatedto the degree of heterogeneity and the incentives of the variousgroups to engage in trading.     

公司治理质量、投资者信心与股票收益

投资者信心保持和提振是一国资本市场获得持续稳定发展的基础。公司治理质量会影响外部投资者的信心吗?投资者信心影响股票收益的机理是什么?本文运用中国A股公司2006-2009年数据进行研究,结果表明,投资者信心是市场层面因素和公司层面因素共同作用的结果。公司治理质量越高,外部投资者信心越强;投资者信心变化通过投资行为形成溢价对股票回报产生影响,这种正向影响在治理质量高的公司中得到增强,在治理质量高的公司中,投资者信心越强,股票回报越大。     

管理层风险提示信息、诚信度与投资者决策——一项实验证据

本文采用实验研究方法,检验了管理层讨论与分析中风险提示信息和管理层的诚信度对投资者估计公司未来盈利潜力和投资可能性的影响。研究发现,管理层讨论与分析中的风险提示信息显著的影响了投资者对上市公司未来盈利潜力的估计和投资者投资可能性的判断;同时还发现,风险提示信息对投资者估计公司未来盈利潜力和投资可能性的影响依赖于公司管理层诚信度的高低,即管理层诚信度调节了公司管理层讨论与分析中风险提示信息对投资者估计上市公司未来盈利潜力和投资可能性的影响。     

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.     

Optimal Life-Cycle Asset Allocation: Understanding the Empirical Evidence

We show that a life‐cycle model with realistically calibrated uninsurable labor income risk and moderate risk aversion can simultaneously match stock market participation rates and asset allocation decisions conditional on participation. The key ingredients of the model are Epstein–Zin preferences, a fixed stock market entry cost, and moderate heterogeneity in risk aversion. Households with low risk aversion smooth earnings shocks with a small buffer stock of assets, and consequently most of them (optimally) never invest in equities. Therefore, the marginal stockholders are (endogenously) more risk averse, and as a result they do not invest their portfolios fully in stocks.     

存在风险条件下的资本市场投资预期收益模型研究

风险是指预期收益的不确定性,是指在将来一段时间内遭受损失的可能性.进行资本市场投资,必然存在风险.资本市场投资风险就是投资预期结果(预期收益损失)的不确定性,有投资风险,就会有投资者对其进行的预期.本文建立了存在风险条件下的资本市场投资预期收益模型,并由此得出了不同投资者的预期收益--风险偏好的不同投资选择.     

Empirical risk aversion functions-estimates and assessment of their reliability

In this paper, we examine investor's risk preferences implied by option prices. In order to derive these preferences, we specify the functional form of a pricing kernel and then shift its parameters until realized returns are best explained by the subjective probability density function, which consists of the ratio of the risk-neutral probability density function and the pricing kernel. We examine, alternatively, pricing kernels of power, exponential, and higher order polynomial forms. Using S&P 500 index options, we find surprising evidence of risk neutrality, instead of risk aversion, in both the power and exponential cases. When extending the underlying assumption on the specification of the pricing kernel to one of higher order polynomial functions, we obtain functions exhibiting ‘monotonically decreasing’ relative risk aversion (DRRA) and anomalous ‘inverted U-shaped’ relative risk aversion. We find, however, that only the DRRA function is robust to variation in sample characteristics, and is statistically significant. Finally, we also find that most of our empirical results are consistent, even when taking into account market imperfections such as illiquidity.     

First-Order Risk Aversion, Heterogeneity, and Asset Market Outcomes

We examine a wide range of two-date economies populated by heterogeneous agents with the most common forms of nonexpected utility preferences used in finance and macroeconomics. We demonstrate that the risk premium and the risk-free rate in these models are sensitive to ignoring heterogeneity. This follows because of endogenous withdrawal by nonexpected utility agents from the market for the risky asset. This finding is important precisely because these alternative preferences have frequently been proposed as possible resolutions to various asset pricing puzzles,  and  they have all been examined exclusively in a representative agent framework.     

The Cross‐Section of Managerial Ability,Incentives, and Risk Preferences

I estimate a dynamic investment model for mutual managers to study the cross‐sectional distribution of ability, incentives, and risk preferences. The manager's compensation depends on the size of the fund, which fluctuates due to fund returns and due to fund flows that respond to the fund's relative performance. The model provides an economic interpretation of time‐varying coefficients in performance regressions in terms of the structural parameters. I document that the estimates of fund alphas are precise and virtually unbiased. I find substantial heterogeneity in ability, risk preferences, and pay‐for‐performance sensitivities that relates to observable fund characteristics.     

中国证券投资基金的需求与其风格“标签”关系的实证分析

对于以组合管理为基本方法的证券投资基金,由于其投资风格选择的不同会导致投资者对其投资偏好的差异,加之证券市场的非有效性和投资者的非完全理性,投资者对基金的投资决策更多基于心理动机和行为因素的判断。本文运用行为组合理论,对我国证券市场封闭式基金的折价状况进行了考察,分析了证券投资基金投资风格选择对基金需求的影响及我国证券市场投资者的需求特点和偏好状况。