Relative risk aversion, relative prudence and comparative statics under uncertainty: The case of (μ, σ)‐preferences

From the expected‐utility approach, relative risk aversion being smaller than one and relative prudence being smaller than two emerge as preference restrictions that fully determine the optimal responses of decisions under uncertainty to certain shifts in probability distributions. We characterize the magnitudes of relative risk aversion and relative prudence in terms of the two‐parameter, mean‐standard deviation approach. We demonstrate that this characterization is instrumental in obtaining comparative static results in the two‐parameter setting. We further relate our findings to the results in the expected‐utility framework.     

Altruism, equity, and reciprocity in a gift-exchange experiment: an encompassing approach

Considerable experimental evidence suggests that non-pecuniary motives must be addressed when modeling behavior in economic contexts. Recent theories of non-pecuniary motives can be classified as altruism-, equity-, or reciprocity-based. We outline the qualitative differences in prediction these alternative explanations yield in a gift-exchange game. We estimate and compare leading approaches in these categories, using experimental data. We then offer a flexible approach that nests the above three approaches, thereby allowing for nested hypothesis testing and for determining the relative strength of each of the competing theories. In addition, the encompassing approach provides a functional form for utility in different settings without the restrictive nature of the approaches nested within it. Using this flexible form for nested tests, we find that intentional reciprocity, distributive concerns, and altruistic considerations all play a significant role in players' decisions.     

Risky allocations from a risk-neutral informed principal

We study a model of informed principal with private values where the principal is risk neutral and the agent is risk averse. We show that the principal, regardless of her type, gains by not revealing her type to the agent through the contract offer. The equilibrium allocation transfers some ex-ante risk from one type of agent to the other. Despite the increase in the principal's surplus, allocative efficiency does not necessarily improve. Received: 26 January 2004, Accepted: 5 May 2005 JEL Classification: C72, D23, D82 I would like to thank my supervisor Leonardo Felli for suggestions and Leo Ferraris for helpful discussions. All remainig errors are my own.     

外资进入对本土企业风险承担的影响：资本逐利还是风险规避

外资自由化作为我国资本市场开放的重要内容,在促进境内外资本要素互联互通的同时,也深刻影响着微观企业行为。以我国2007—2017年A股上市公司作为研究样本,实证检验外资进入对我国本土企业风险承担的影响。研究发现：外资进入能够显著提升企业的风险承担水平。进一步地,外资进入对企业风险承担的促进效应在融资约束严重、股权集中度更高和市场化进程缓慢地区的企业中更加显著。此外,在不同资本市场开放水平,外资进入对企业风险承担的作用存在明显差异。     

A Bayesian approach for more reliable tail risk forecasts

This paper demonstrates that existing quantile regression models used for jointly forecasting Value-at-Risk (VaR) and expected shortfall (ES) are sensitive to initial conditions. Given the importance of these measures in financial systems, this sensitivity is a critical issue. A new Bayesian quantile regression approach is proposed for estimating joint VaR and ES models. By treating the initial values as unknown parameters, sensitivity issues can be dealt with. Furthermore, new additive-type models are developed for the ES component that are more robust to initial conditions. A novel approach using the open-faced sandwich (OFS) method is proposed which improves uncertainty quantification in risk forecasts. Simulation and empirical results highlight the improvements in risk forecasts ensuing from the proposed methods.     

Completing the State Space with Subjective States

We define an opportunity act as a mapping from an exogenously given objective state space to a set of lotteries over prizes, and consider preferences over opportunity acts. We allow the preferences to be possibly uncertainty averse. Our main theorem provides an axiomatization of the maxmin expected utility model. In the theorem we construct subjective states to complete the objective state space. As in E. Dekel et al. (Econometrica, in press), we obtain a unique subjective state space. We also allow for preference for flexibility in some of the subjective states and commitment in others. Journal of Economic Literature Classification Number: D81.     

Discrepancies between ex ante and ex post efficiency under identical subjective probabilities

Summary. Starr (1973) showed that, if people have different subjective probabilities, ex ante and ex post efficiency conflict. Conversely, under the simple preferences that he considered, the discrepancy between ex ante and ex post efficiency disappears when subjective probabilities are identical. Here I consider identical subjective probabilities, but more general preferences. First, risk attraction is admitted. Second, I dispense with the double requirement (dubbed IZU) of additive separability and state-independence of the utility of zero-date consumption, an unrealistic requirement when modeling the investment in durable goods. I find that, under IZU, and as long as ex post preferences satisfy the natural assumption of quasiconcavity (and satisfy some technical qualifications), an ex ante efficient allocation is indeed ex post efficient, but the converse is not necessarily true under risk attraction. If, on the other hand, IZU is violated, then one can have ex ante efficient allocations that are not ex post efficient, and vice-versa, even under risk aversion. Received: June 25, 1999; revised version: March 2001     

Risk aversion and the dynamics of optimal liquidation strategies in illiquid markets

We consider the infinite-horizon optimal portfolio liquidation problem for a von Neumann–Morgenstern investor in the liquidity model of Almgren (Appl. Math. Finance 10:1–18, 2003). Using a stochastic control approach, we characterize the value function and the optimal strategy as classical solutions of nonlinear parabolic partial differential equations. We furthermore analyze the sensitivities of the value function and the optimal strategy with respect to the various model parameters. In particular, we find that the optimal strategy is aggressive or passive in-the-money, respectively, if and only if the utility function displays increasing or decreasing risk aversion. Surprisingly, only few further monotonicity relations exist with respect to the other parameters. We point out in particular that the speed by which the remaining asset position is sold can be decreasing in the size of the position but increasing in the liquidity price impact.      

解读“穷人思维”:贫困农户风险态度的影响因素分析——来自广西、贵州贫困山区入户实地实验的证据

采用入户实地实验的方式,从贫困农户风险态度的影响因素入手对"穷人思维"进行解读。在广西、贵州两个少数民族聚居乡（镇）进行的抽样调查和实验发现,贫农普遍厌恶风险,特别在面临可能的损失时风险厌恶程度显著上升,但也有部分风险偏好者,在面临可能的损失时却更为偏好风险;越是厌恶风险者获得的实验收益越低,相反越是偏好风险者获得的实验收益越高;配偶、母亲受教育水平的增加显著降低了贫农的风险厌恶程度;家庭承受的教育负担越重,贫农的风险厌恶程度越高。扶贫政策的开展和实施应考虑贫农的风险态度,完善针对风险偏好者的多样化的金融支持和针对风险厌恶者的低息金融扶持,能覆盖更广泛的贫农群体。长期来看,教育扶贫应当成为一项持续的重点扶贫政策,降低家庭教育负担、提高女性的受教育年限、加强成人继续教育培训都将产生长期、积极的显著影响。