Risk attitudes, randomization to treatment, and self-selection into experiments

Randomization to treatment is fundamental to statistical control in the design of experiments. However randomization implies some uncertainty about treatment condition, and individuals differ in their preferences towards taking on risk. Since human subjects often volunteer for experiments or are allowed to drop out of the experiment at any time if they want to, it is possible that the sample observed in an experiment might be biased because of the risk of randomization. On the other hand, the widespread use of a guaranteed show-up fee that is non-stochastic may generate sample selection biases of the opposite direction, encouraging more risk averse samples into experiments. We directly test these hypotheses that risk attitudes play a role in sample selection. Our results suggest that randomization bias does affect the overall level of risk aversion in the sample we observe, but that it does not affect the demographic mix of risk attitudes in the sample. We show that the common use of non-stochastic show-up fees can generate samples that are more risk averse than would otherwise have been observed.     

Risk and risk aversion when states of nature matter

When uncertainty is associated with some intrinsically relevant states of nature, there is no reason for an agent to base his or her preferences only on probability distribution of claims. We propose a new concept of risk for state-contingent claims that, unlike the standard concept of Rothschild–Stiglitz, does not identify state-contingent claims with their probability distribution. This concept is called mean-independent risk, and we provide a simple characterization in terms of marginal utilities of (non-expected) utility functions that exhibit aversion to mean-independent risk. We study implications of aversion to mean-independent risk on agents’ choices under uncertainty. This research has been supported by the NSF under Grant SES-0099206. I have benefited from numerous conversations with Rose-Anne Dana and illuminating discussions with Tadeusz Miłosz about the theory of subgradients.     

企业价格战对顾客交易价值的影响

通过情景模拟实验讨论了降价因素对于己购买产品的顾客在交易价值感知上带来的影响,研究的主要发现有:顾客购后仍然会进行交易价值判断,顾客的可接受降价幅度受到使用时间和心理折旧等因素的影响,在一定时间内,当市场实际降价幅度超过顾客的合理降价预期时,顾客的交易价值感受将受到负面影响。     

Properties of the utility function: A market-based analysis

Using US market data, this paper sheds new empirical light on properties of the utility function. In particular, employing theoretical relations between Stochastic Discount Factors, state prices, and state probabilities, we are successful in recovering the following four functions: (i) Absolute Risk Aversion (ARA); (ii) Absolute Risk Tolerance (ART); (iii) Absolute Prudence (AP); and (iv) Absolute Temperance (AT). Our statistical analysis points out, unequivocally, that the ARA function is decreasing and convex, the ART function is convex, AT is greater than ARA, and the AP function is not decreasing. These empirical results are analyzed in light of established theory concerning, inter-alia, precautionary saving and prudence as well as the way risk attitudes are affected by the presence of “background risks” and by investors’ investment horizon.     

中国货币政策的福利损失及中介目标的选择——基于新凯恩斯DSGE模型的分析

文章运用新凯恩斯框架下的DSGE模型对中国货币政策的福利损失进行分析,研究表明:(1)名义利率对通货膨胀的反应越是敏感,则福利损失越小,因此,货币当局应该充分利用利率政策稳定价格水平;(2)名义利率对产出的反应越是敏感,则福利损失越大,因此,货币当局不宜运用利率政策影响经济增长速度;(3)利率平滑对福利的影响不大,货币当局的利率政策应该直接针对通货膨胀,而不应该追求利率本身的稳定;(4)在一定条件下,不同的利率政策规则造成的福利损失差别不大,货币当局可以从便利的角度出发,根据上期的通货膨胀率和产出水平来设定当期的名义利率;(5)与利率变动相比,货币供应量的变动造成福利损失更大,因此,货币政策的中介目标应该逐步由货币供应量转向利率。     

关于自然资源的价值、价格问题

本文较详细地讨论了自然资源的价值与价格,提出了新的自然资源价值观。具有价值属性的自然资源一般有价值,其基本特点是:同类、同类而不同质及不同类型的资源的价值量可以相等也可以不等。自然资源的价格不是价值的货币表现。自然资源的价值与价格矛盾导致新的价值观:自然资源的价值不是自然资源财富的真正价值,它的真正价值是财富价值,而价格则是财富价值的货币表现。财富价值由把资源作为生产要素使用时产生的收益大小决定,资源作为商品在进行交换时以财富价值为基础。财富价值又可划分为两部分:损益价值和效益价值。新的价值观对于使自然资源的核算与整个国民经济核算体系紧密衔接、对于经济规律的再认识等都具有重要的意义。     

金融海啸对世界寿险业的风险警示

我国寿险业在这次金融危机中受到一定影响,但没有造成全局性、系统性风险。金融危机对我国寿险业来说是一个调整契机：业务结构调整应当突出寿险业作为提供风险管理和风险保障者安身立命的行业特性,引导行业首先要保持和发挥自身的行业特性,重回寿险业独立的核心价值定位;避免降息对利差损造成的风险;积极改变投资策略,减少资本市场风险带来的收益波动;加强监管,避免系统性风险。     

基于渔业生态损失评价的渔业生态补偿机制研究

渔业生态损失是指人类在开发利用海洋资源的过程中所造成的渔业生态资源价值的损失,是实施渔业生态补偿的依据。本文在分析渔业生态损失过程的基础上,将渔业生态损失分为渔业资源损失和渔业环境质量损失,采用环境影响经济评价的方法来评估渔业生态损失的价值量,以这一价值量作为确定渔业生态补偿标准的依据,并从分析渔业生态补偿主体和补偿对象的界定、补偿方式与手段的选择等方面来研究渔业生态补偿机制的问题。     

A note on estimation based on record data

In data-processing standpoint, an efficient algorithm for identifying the minimum value among a set of measurements are record statistics. From a sequence of n independent identically distributed continuous random variables only about log(n) records are expected, so we expect to have little data, hence any prior information is welcome (Houchens, Record value theory and inference, Ph.D. thesis, University of California, Riverside, 1984). In this paper, non-Bayesian and Bayesian estimates are derived for the two parameters of the Exponential distribution based on record statistics with respect to the squared error and Linear-Exponential loss functions and then compared with together. The admissibility of some estimators is discussed.     

Regulating Nitrogen Pollution with Risk Averse Farmers under Hidden Information and Moral Hazard

We consider a model of pollution regulation for a risk averse farmer involving hidden information, moral hazard, and risk-sharing. The representative farmer faces a production risk originating from nitrogen leaching, and privately observes the soil capacity in retaining nitrogen only after the regulation contract is signed. The latter specifies a transfer and a nitrogen quota, whose decomposition by the farmer among different production stages is unknown to the regulator. We first characterize the optimal solution to the regulator's problem. The sequential decision model is estimated on French crop production data, and the results are used to calibrate and simulate the optimal contract.