Differences Between Short‐ and Long‐Term Risk Aversion: An Optimal Asset Allocation Perspective

This paper studies the long‐term asset allocation problem of an investor with different risk aversion attitudes to the short and the long term. We characterize investor's preferences with a utility function exhibiting a regime shift in risk aversion at some point of the multiperiod investment horizon that is estimated using threshold nonlinearity methods. Our empirical results for a portfolio of cash, bonds and stocks suggest that long‐term risk aversion is higher than short‐term risk aversion and increases with the investment horizon. The exposure of the investment portfolio from stocks to bonds and cash increases with the degree of risk aversion.     

Homeownership and mixed-asset portfolio allocations

Homeownership represents both a consumption and an investment decision for individuals. Considering the investment benefits of the home, we estimate the total returns and risk associated with the investment in single-family homes. Then, using a mean–variance utility function, we consider the impact of homeownership and mortgage loan financing on the optimal asset allocation decisions of individuals and contrast this with advice that does not include the home as part of the portfolio. While optimal portfolio weights are dependant upon both the degree of risk aversion of the individual investor and the relative importance of the home in the overall net worth picture, we show that, in general, the higher the home-to-net worth ratio, the higher the optimal portfolio allocation to stock. For most investors, including the home in the optimization decision leads to higher allocations to risky stock than suggested by traditional advice that ignores the home.     

International Portfolio Diversification and the Magnitude of the Market Timer's Penalty

Market timers without timing skill suffer a penalty relative to buy-and-hold investors in the form of higher portfolio risk. With transactions costs, timers suffer lower expected returns as well. We derive the magnitude of this penalty for a timer randomly switching funds between two or more risky assets. Assuming costless trades, a U.S.-based timer randomly switching between U.S. and Japanese national stock funds can expect to face a 26.2% higher standard deviation than a comparable buy-and-hold investor at the same level of expected return. A timer randomly switching between a globally diversified equity portfolio and U.S. T-bills faces a 50.3% higher standard deviation of return than a comparable buy-and-hold investor.     

投资者结构模式变迁与市场流动性风险

本文研究了市场流动性风险与投资者结构模式之间的关系。随着机构投资者的不断发展壮大,我国投资者结构模式发生了重要转变,然而新的投资者结构模式下,市场流动性的波动结构是否有所不同？本文以流动性水平变化率为研究对象,构建了包含虚拟变量的TGARCH模型对其波动方程进行拟合,研究发现：机构投资者壮大后市场流动性风险显著降低;机构占主导后市场流动性风险受新信息的影响权重较之前增大,而旧有信息对流动性风险的影响相比以前减小。     

Do High‐Frequency Data Improve High‐Dimensional Portfolio Allocations?

This paper addresses the debate about the usefulness of high‐frequency (HF) data in large‐scale portfolio allocation. We construct global minimum variance portfolios based on the constituents of the S&P 500. HF‐based covariance matrix predictions are obtained by applying a blocked realized kernel estimator, different smoothing windows, various regularization methods and two forecasting models. We show that HF‐based predictions yield a significantly lower portfolio volatility than methods employing daily returns. Particularly during the 2008 financial crisis, these performance gains hold over longer horizons than previous studies have shown, translating into substantial utility gains for an investor with pronounced risk aversion. Copyright © 2013 John Wiley & Sons, Ltd.     

组合投资风险规避策略分析

高新技术产业发展呼唤风险投资,但是风险投资具有高风险性和高收益性。本文分析了风险投资风险规避策略中的 组合投资策略及现实意义。     

Forecasting stock market volatility: Can the risk aversion measure exert an important role?

In this paper, we predict realized volatility of stock return by utilizing time-varying risk aversion based on a simple linear autoregressive model. Our in-sample results suggest that time-varying risk aversion have significant impact for stock return volatility. In terms of out-of-sample forecasting performance, the empirical results indicate that the incorporation of time-varying risk aversion in the benchmark model can yield more accurate stock return volatility forecasts. Notably, the out-of-sample forecasting results confirm that our conclusions are robust when we apply alternative lag orders and alternative prediction evaluation periods. Finally, we study links between the prediction ability of time-varying risk aversion and the volatility of other stock indices and two kinds of crude oil, and find that the new predictor can effectively strengthen forecasting performance in most case. In view of the importance of volatility risk in the asset pricing process, our research is of great significance for financial asset participants.     

A model of international asset pricing under imperfect commodity arbitrage

This paper examines the effect of imperfect international commodity arbitrage (i.e., violation of the law of one price), modeled as the existence of non-traded goods, on the structure of purchasing power risk, optimal portfolio rules of the risk-averse investors and the equilibrium yield relationship among assets. The major results of the paper include: (i) There are two separate sources of purchasing power risk, i.e., relative price risk and inflation risk; relative price risk is specific to the country in which the investor resides. (ii) In a world of n countries, investors may hold n + 1 hedge portfolios as vehicles to hedge against purchasing power risk; facing different relative prices, investors residing in different countries display divergent portfolio behavior. (iii) In equilibrium, investors are compensated in terms of excess return for bearing not only the systematic world market risk but also the systematic inflation and relative price risks.     

中国无风险利率之谜与股权溢价

按照传统的消费资本资产定价理论,中国股市的高股权溢价只能由投资者的高相对风险厌恶系数来解释。但是这又会产生所谓的无风险利率之谜,因为投资者相对风险厌恶系数高时,其时间偏好率为负,明显不合情理。     

DETERMINANTS OF PUBLIC PENSION PLAN INVESTMENT RETURN. The role of fund value maximization and public choice theory

Public pension plans are a major type of institutional owner during the new era of investor capitalism, yet little is known about them. Based upon fund value maximization (FVM) and public choice theory (PCT), we develop hypotheses on the determinants of plan performance as measured by plan annual investment return. FVM espouses that the plan's fund or investment portfolio will be invested to maximize return for a given level of risk, while PCT holds that agency costs are significant in the public sector, and will have a negative effect on plan return. Using biennial pension plan data for 1992–96 for several hundred plans, we found that fund value maximization has a much greater influence on plan performance, but that plan performance is also subject to agency costs associated with public choice theory.     

Optimal portfolio choice in the presence of domestic systemic risk: empirical evidence from stock markets

In this paper, we empirically investigate the consequences of domestic systemic risk for stock market investors. To tackle this issue, we consider two different investment strategies. One strategy is to be “crisis-conscious”, i.e., taking the possibility of systemic events into account, and the other one is to be “crisis-ignorant” and thus disregarding systemic risk. We compare the optimal portfolio choices and investment results of these strategies in an historical simulation, using almost three decades of historical stock price data. Our main findings are as follows: the crisis-conscious investor tends to choose less extreme portfolio weights for individual stocks than the ignorant investor. The overall risky investment is, however, of similar size for both. By ignoring the possibility of systemic events, the crisis-ignorant strategy performs significantly worse from the viewpoint of expected return as well as expected utility.     

Investor co-attention and stock return co-movement: Evidence from China’s A-share stock market

This study attempts to link investor co-attention to stock return co-movement in China's A-share stock market. On the one hand, stock price will co-move for stocks within the same industry and within the same market, which is labelled “return co-movement”. On the other hand, investor attention will also co-move as investors systematically search for relevant information for stocks of similar characteristics or as the stocks experience common information shocks, which is termed “investor co-attention”. The empirical evidence suggests that stock return co-movement can be explained by investor co-attention to a great extent, even after controlling for stock fundamentals and firm characteristics, and this effect is more salient for stocks with lower institutional ownership. Moreover, we employ large national lottery jackpots as exogenous shocks to investor attention. The empirical findings show that the co-movement of both investor attention and stock return increase on large lottery jackpot days, while investor co-attention contributes less to return co-movement on large lottery jackpot days. In summary, we offer an alternative explanation for return co-movement by observing the causal relationship between investor co-attention and stock return co-movement.     

基于投资组合理论的企业多项目投资管理研究

投资行为所具有的风险和收益密切相关的特点,使投资者必须努力寻求低风险和高收益的投资策略。而投资组合则能够为企业进行分散风险和扩张经营提供强有力的保证。本文使用现代投资组合理论,为企业的多项目投资组合建立优化模型,从定量的角度说明在企业多项目投资管理中运用投资组合的合理性和有效性。     

On the nature of certainty equivalent functionals

We explore connections between the certainty equivalent return (CER) functional and the underlying utility function. Curvature properties of the functional depend upon how utility function attributes relate to hyperbolic absolute risk aversion (HARA) type utility functions. If the CER functional is concave, i.e., if risk tolerance is concave in wealth, then preferences are standard. The CER functional is linear in lotteries if utility is HARA and lottery payoffs are on a line in state space. Implications for the optimality of portfolio diversification are given. When utility is concave and non-increasing relative risk averse, then the CER functional is superadditive in lotteries. Depending upon the nature of association among lottery payoffs, CERs for constant absolute risk averse utility functions may be subadditive or superadditive in lotteries. Our approach lends itself to straightforward experiments to elicit higher order attributes on risk preferences.     

On the nature of certainty equivalent functionals

We explore connections between the certainty equivalent return (CER) functional and the underlying utility function. Curvature properties of the functional depend upon how utility function attributes relate to hyperbolic absolute risk aversion (HARA) type utility functions. If the CER functional is concave, i.e., if risk tolerance is concave in wealth, then preferences are standard. The CER functional is linear in lotteries if utility is HARA and lottery payoffs are on a line in state space. Implications for the optimality of portfolio diversification are given. When utility is concave and non-increasing relative risk averse, then the CER functional is superadditive in lotteries. Depending upon the nature of association among lottery payoffs, CERs for constant absolute risk averse utility functions may be subadditive or superadditive in lotteries. Our approach lends itself to straightforward experiments to elicit higher order attributes on risk preferences.     

Investors' carbon risk exposure and their potential for shareholder engagement

This article examines the exposure to and management of carbon risks of different investor types. Considering the dual role as portfolio manager and partial owner, we analyze carbon risk for investors both in terms of exposure to portfolio values and in terms of responsibility as shareholder of carbon-intensive firms. We show that among various investor types, the preference for holding carbon-intensive stocks differs substantially, even when considering traditional investment decision parameters. In particular, it is governments whose portfolio values are most threatened by a carbon risk exposure of 49%, but at the same time, they prefer larger ownership shares in polluting firms. In contrast, individual investors, investment advisors, and mutual funds avoid holding stakes in these firms, while revealing only a moderate exposure of their assets to carbon risk. In view of the Paris Agreement, which includes the consistent steering of financial flows towards a low carbon transformation of the economy, our study provides policymakers with important implications regarding the coverage and effects of respective regulations. By identifying the ownership structures of carbon-intensive firms and respective owners' portfolio compositions, we also offer implications for further research on portfolio decarbonization and shareholders' influence of corporate carbon management.     

Consumption-based CAPM with belief heterogeneity

This paper finds that the risk–return relationship of the consumption-based CAPM is robust to the heterogeneity in agents׳ beliefs. First, the effect of disagreement cancels out in the limit as risk tolerance approaches zero. Second, although low risk aversion and large disagreement can significantly distort the security market line (SML) and the effect is amplified in a dynamic model, per capita volatility of consumption growth is implausibly high compared to empirical estimates from microeconomic data. Third, increasing risk aversion and lowering disagreement levels can help to reduce per capita volatility, however the impact of disagreement on the SML also become negligible.     

Optimal consumption and investment under time-varying relative risk aversion

We consider the continuous time consumption-investment problem originally formalized and solved by Merton in case of constant relative risk aversion. We present a complete solution for the case where relative risk aversion with respect to consumption varies with time, having in mind an investor with age-dependent risk aversion. This provides a new motivation for life-cycle investment rules. We study the optimal consumption and investment rules, in particular in the case where the relative risk aversion with respect to consumption is increasing with age.     

Predictability of stock returns and asset allocation under structural breaks

This paper adopts a new approach that accounts for breaks to the parameters of return prediction models both in the historical estimation period and at future points. Empirically, we find evidence of multiple breaks in return prediction models based on the dividend yield or a short interest rate. Our analysis suggests that model instability is a very important source of investment risk for buy-and-hold investors with long horizons and that breaks can lead to a negative slope in the relationship between the investment horizon and the proportion of wealth that investors allocate to stocks. Once past and future breaks are considered, an investor with medium risk aversion reduces the allocation to stocks from close to 100% at short horizons to 10% at the five-year horizon. Welfare losses from ignoring breaks can amount to several hundred basis points per year for investors with long horizons.     

Rational plunging and the option value of sequential investment: The case of petroleum exploration

The potential to invest sequentially in related assets creates a tradeoff between diversification and concentration. Loading a portfolio with correlated assets has the potential to inflate variance, but also creates information spillovers and real options that may augment total return and mitigate variance. We examine this tradeoff in the context of petroleum exploration. Using a simple model of geological dependence, we show that the value of learning options creates incentives for investors to plunge into dependence; i.e., to assemble portfolios of highly correlated exploration prospects. Risk-neutral and risk-averse investors are distinguished not by the plunging phenomenon, but by the threshold level of dependence that triggers such behavior. Aversion to risk does not imply aversion to dependence. Indeed the potential to plunge should be larger for risk-averse investors than for risk-neutral investors. We test the empirical validity of our theory by examining bidding activity in petroleum lease sales. We find significant plunging behavior across a broad sample of oil companies. We also find that privately-held firms pursue even more concentrated (less diversified) prospect portfolios than publicly-held firms—which we attribute to risk aversion rather than size.