Risk aversion and allocation to long-term bonds

As risk aversion approaches infinity, the portfolio of an investor with utility over consumption at time T is shown to converge to the portfolio consisting entirely of a bond maturing at time T. Previous work on bond allocation requires a specific model for equities, the term structure, and the investor's utility function. In contrast, the only substantive assumption required for the analysis in this paper is that markets are complete. The result, which holds regardless of the underlying investment opportunities and the utility function, formalizes the “preferred habitat” intuition of Modigliani and Sutch (Amer. Econom. Rev. 56 (1966) 178).     

基金的业绩评估与组合管理

基于对国际上通用的基金事后业绩评估指标、事前预期收量评估指标以及基金在组合投资时常用的夏普准则的分析，并结合我国的实际情况认为，基金定期公布其周收益的标准差或组合的加权Beta值，有利于投资者更加全面地衡量基金的业绩。同时，对基金管理人而言，将风险调整收益应用到基金组合管理中来，有利于增强基金的抗风险能力，以保持基金的长期稳定的增长。     

Delegated portfolio management and optimal allocation of portfolio managers

In this article, we investigate whether the application of the mean-variance framework on portfolio manager allocation offers any out-of-sample benefits compared to a naïve strategy of equal weighting. Based on an exclusive data-set of high-net-worth (HNW) investors, we utilize a wide variety of methodologies to estimate the input parameters including exponentially weighted moving average (EWMA), generalized autoregressive conditional heteroscedasticity (GARCH) and Bayes–Stein shrinkage estimation. We apply nine different mean-variance models, but find that none of these present any consistent benefit over a naïve strategy of equal weighting.     

Liquidity risk and bank portfolio allocation

The joint existence of a lender of last resort and of a stock market is usually considered the sign of a developed financial infrastructure. This paper analyzes whether a securities market may play a role similar to that of a lender of last resort by being of assistance to a bank, which faces possible liquidity shortages. We examine which of these two institutions best prevents a bank's liquidity shortages while allowing the optimal allocation of the bank's resources. Our results suggest that securities markets matter more for the liquidity of banks than a lender of last resort.     

Risk aversion and self-insurance

This paper considers the effects of an increase in risk aversion on self-insurance. More risk-averse individuals invest more in self-insurance in the case of two states of the world. However, with more than two states, this standard conclusion does not hold. The reason is that self-insurance does not necessarily reduce larger losses more effectively than smaller losses. Self-insurance thus may not serve as insurance, and more risk-averse individuals may invest more or less in self-insurance. The paper provides a condition for more risk-averse individuals to invest more in self-insurance, and a condition for them to invest less.     

Fuzzy multi-criteria decision-making for evaluating mutual fund strategies

Investors often need to evaluate investment strategies according to their own subjective preferences based upon various criteria. This situation can be regarded as a Fuzzy Multiple Criteria Decision-Making (FMCDM) problem. The purpose of this study is to propose an FMCDM approach with fuzzy integral. This approach relaxes the independence assumption among criteria for the evaluation of the Multiple Criteria Decision-Making (MCDM) problems, which is oftentimes the basic assumption in applying hierarchical system for evaluating the strategies of selecting investment style. We also employ Triangular Fuzzy Numbers (TFNs) to represent the decision-makers’ subjective preferences on the criteria, as well as for the criteria measurements to evaluate mutual funds investment style. To achieve this objective, first, we employ factor analysis to extract four independent common factors from those criteria. Second, we construct the evaluation frame using hierarchical system composed of four common factors with 16 evaluation criteria, and then derive the relative weights with respect to the considered criteria. Third, the synthetic utility value corresponding to each mutual fund's investment style is aggregated by the fuzzy weights with fuzzy performance values. Finally, we compare with empirical data and find that the model of FMCDM predicts the rate of return very accurately in certain ranges of λ, hence the nonadditive fuzzy integral technique is an effective method for evaluating mutual funds’ strategy.     

Increases in risk aversion and the distribution of portfolio payoffs

Oliver Hart proved the impossibility of deriving general comparative static properties in portfolio weights. Instead, we derive new comparative statics for the distribution of payoffs: A is less risk averse than B iff A?s payoff is always distributed as B?s payoff plus a non-negative random variable plus conditional-mean-zero noise. If either agent has nonincreasing absolute risk aversion, the non-negative part can be chosen to be constant. The main result also holds in some incomplete markets with two assets or two-fund separation, and in multiple periods for a mixture of payoff distributions over time (but not at every point in time).     

Risk aversion and framing effects

We present a new experimental evidence of how framing affects decisions in the context of a lottery choice experiment for measuring risk aversion. We investigate framing effects by replicating the Holt and Laury’s (Am. Econ. Rev. 92:1644–1655, 2002) procedure for measuring risk aversion under various frames. We first examine treatments where participants are confronted with the 10 decisions to be made either simultaneously or sequentially. The second treatment variable is the order of appearance of the ten lottery pairs. Probabilities of winning are ranked either in increasing, decreasing, or in random order. Lastly, payoffs were increased by a factor of ten in additional treatments. The rate of inconsistencies was significantly higher in sequential than in simultaneous treatment, in increasing and random than in decreasing treatment. Both experience and salient incentives induce a dramatic decrease in inconsistent behaviors. On the other hand, risk aversion was significantly higher in sequential than in simultaneous treatment, in decreasing and random than in increasing treatment, in high than in low payoff condition. These findings suggest that subjects use available information which has no value for normative theories, like throwing a glance at the whole connected set of pairwise choices before making each decision in a connected set of lottery pairs.     

An algebraic theory of portfolio allocation

Summary. Using group and majorization theory, we explore what can be established about allocation of funds among assets when asymmetries in the returns vector are carefully controlled. The key insight is that preferences over allocations can be partially ordered via majorized convex hulls that have been generated by a permutation group. Group transitivity suffices to ensure complete portfolio diversification. Point-wise stabilizer subgroups admit sectoral separability in fund allocations. We also bound the admissible allocation vector by a set of linear constraints the coefficients of which are determined by group operations on location and scale asymmetries in the rate of returns vector. For a distribution that is symmetric under a reflection group, the linear constraints may be further strengthened whenever there exists an hyperplane that separates convex sets. Received: May 15, 2001; revised version: March 20, 2002 RID="*" ID="*" Journal paper No. J-19797 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 3463, and supported by Hatch Act and State of Iowa funds. Correspondence to: D. A. Hennessy     

Aggregation, efficiency and mutual fund separation in incomplete markets

Summary. This paper studies the conditions for aggregation, portfolio separation and effective completeness of competitive allocations in general equilibrium models with incomplete markets where agents have general preference and endowment distributions. We show that these properties are distinct. Demands may aggregate yet may fail to exhibit fund separation and conversely. Fund separation implies effective completeness while aggregation does not. The implications of these properties for the structure of equilibria are discussed, and generalizations of the CAPM, the consumption CAPM and the CAPM with nonmarketed wealth emerge from the analysis. Received: September 12, 1996; revised version: November 7, 1996     

Risk breeds risk aversion

We examine whether exposure to a more or less risky environment affects people’s subsequent risk-taking behavior. In a laboratory setting, all subjects went through twelve rounds of multiple-price-list decisions between a risky alternative and a safe alternative. In the first six rounds, subjects were randomly assigned to a high-, moderate-, or low-risk environment, which differed in the variances of the lotteries they were exposed to. In the last six rounds, subjects in all treatments made decisions on an identical set of lotteries. We found that subjects who had experienced a riskier environment exhibited a higher degree of risk aversion. Our experimental design allows us to conclude that this effect is driven by the risk environment per se, rather than the realized outcomes of the risk. This finding has important theoretical and policy implications.     

Symmetry and order in the portfolio allocation problem

Summary. This research studies the role of multivariate distribution structures on random asset returns in determining the optimal allocation vector for an expected utility maximizer. All our conclusions pertain for the set of risk averters. By carefully disturbing symmetry in the distribution of the, possibly covarying, returns, we ascertain the ordinal structure of the optimized allocation vector. Rank order of allocations is also established when a permutation symmetric random vector is mapped into the returns vector through location and scale shifts. It is shown that increased dispersion in the vectors of location and scale parameters benefit, ex-ante, investors as does a decrease in the rank correlation coefficient between the location and scale parameter vectors. Revealed preference comparative static results are identified for the location and scale vectors of asset returns. For most issues addressed, we arrive at much stronger inferences when a safe asset is available. Received: August 8, 2000; revised version: January 8, 2001     

我国养老保险基金进入资本市场的投资组合模式构造

养老保险基金是养老保险制度存在和发展的物质基础和前提条件。养老保险基金的负债性质，决定了养老保险基金应在确保安全性的前提下进入资本市场，通过科学、有效的资产组合管理，实现养老保险基金在积累不断扩大前提下的保值、增值。     

Risk aversion in the Eurozone

We propose a New Keynesian Dynamic Stochastic General Equilibrium (DSGE) model where a risk aversion shock enters a separable utility function. We analyze five periods from 1971 through 2011, each lasting for 20 years, to follow over time the dynamics of several parameters such as the risk aversion parameter; the Taylor rule coefficients; and the role of the risk aversion shock in output, inflation, interest rate, and real money balances in the Eurozone. Our analysis suggests that risk aversion was a more important component of output and real money balance dynamics between 2006 and 2011 than it was between 1971 and 2006, at least in the short run.     

Risk aversion in the Talmud

Summary. Evidence is adduced that the sages of the ancient Babylonian Talmud, as well as some of the medieval commentators thereon, were well aware of sophisticated concepts of modern theories of risk-bearing. Received: April 10, 2002; revised version: May 7, 2002 RID="*" ID="*"Presented at the Institute for Mathematical Studies in the Social Sciences-Economics, Stanford University, August 4, 1981. Subsequent to that presentation, the author's attention was drawn to an article by Zvi Ilani, “Models in the Economics of Uncertainty: The Cost of Concluding a Conditional Contract, according to the Talmud and the Halachic Literature,” Iyunim Bekalkala (Investigations in Economics), The Israel Association for Economics, Jerusalem, Nissan 5740 (April 1980), 246–261 (in Hebrew). Inter alia, Ilani treats the Talmudic passage that forms the subject of this paper, and provides a fairly comprehensive review of the medieval commentaries thereon; undoubtedly, he was the first to recognize in print the relevance of this passage to modern economic theories of uncertainty. It is not clear, though, whether or not his understanding of the passage agrees with ours. The current paper appeared in January 2002 in the Research Bulletin Series of the Research Center on Jewish Law and Economics, Department of Economics, Bar Ilan University.     

基金公司督察员的角色定位

在我国的基金管理公司中,按现行规定,有一个很特别的角色——督察员,其职能是全权负责管理公司的监察稽核工作。督察员的任免应报中国证监会核准。督察员可列席管理公司的任何会议,对基金运作、内部管理、制度执行及遵规守法情况进行内部监察、稽核,并独立出具稽核报告,报送中国证监会和管理公司的董事长;如发现管理公司有重大违规行为,应立即向中国证监会报告。根据这些规定,我们可以给出现行的督察员的职能定位。