不确定性与投资:实物期权还是冒险行为

文章依据公司不确定性与投资关系的实物期权理论与代理理论,从公司债务期限结构、投资不可逆性、公司成长性、财务困境和股权激励五个维度,提出风险投资关系及其影响因素的检验命题,并利用中国上市公司数据分析得到结果。研究结果表明,中国民营上市公司存在较强的投资风险规避倾向,但这种关系在存在财务困境和股权激励的公司表现减弱。国有上市公司存在相似的现象但显著性相对不明显。     

Trust, trustworthiness, and risk in rural Paraguay

This dissertation looks at the relationship between trust, trustworthiness, and risk aversion in a rural Paraguayan setting. The first chapter of this dissertation looks at theft between farmers. Rural areas of developing countries often lack effective legal enforcement. However, villagers who know each other well and interact repeatedly may use implicit contracts to minimize crime. I construct a dynamic limited-commitment model in which a thief cannot credibly commit to forego stealing from his fellow villagers but may be induced to limit his stealing by the promise of future gifts from his potential victim. Using a unique survey from rural Paraguay which combines traditional data on production with information on theft, gifts, and trust, as well as with experiments measuring trust and trustworthiness, I test whether the data is consistent with predictions from the dynamic model. The results provide evidence that, in contrast with predictions from a one-period model with an anonymous thief, farmers do implicitly contract with one another to limit theft. Farmers who have more close family members in their village give fewer gifts, and farmers with plots which are more difficult to steal from give fewer gifts, experience less theft, and trust more. Gift-giving increases when trust is lower and the threat of theft is greater, turning the social capital literature on its head. The second chapter of this dissertation looks at a different linkage between trust, trustworthiness, and risk. Trusting behavior in general and play in the traditional trust experiment specifically depend both on trust beliefs and on levels of risk aversion. I ran two experiments with a diverse set of subjects in fifteen villages of rural Paraguay, the traditional trust experiment and a new experiment measuring only risk aversion. I find that risk attitudes are highly predictive of play in the trust game. In addition, omitting risk aversion as a regressor in trust regressions significantly changes the coefficients of important explanatory variables such as gender and wealth. The chair of this dissertation committee was Ethan Ligon and the other committee members were George Akerlof and Elisabeth Sadoulet.     

Risk preference and indirect utility in portfolio-choice problems

We consider a portfolio-choice problem with one risky and one safe asset, where the utility function exhibits decreasing absolute risk aversion (DARA). We show that the indirect utility function of the portfolio-choice problem need not exhibit DARA. However, if the (optimal) marginal propensity to invest is positive for both assets, which is true when the utility function exhibits nondecreasing relative risk aversion, then the DARA property is carried over from the direct to the indirect utility function.     

管理浮动汇率制背景下人民币名义汇率波动分析

本文运用描述统计方法比较了1994年1月至1997年12月、2005年7月至今管理浮动汇率制背景下两个不同阶段内人民币/美元汇率波动的情况,而后结合中国实际、采用自回归分布滞后方法建模,分析了2005年汇改新政之后影响汇率波动变化的因素。     

Risk aversion and prudence in the large

The familiar measures of absolute and relative risk aversion constructed by Pratt and Arrow, along with the measures of absolute and relative prudence inspired by Leland and later developed by Kimball, are local instruments based on the first and second derivatives of utility at a specific level of wealth. As such, they are applicable only to infinitesimal risks—those for which differential calculus is a suitable analytical tool. Consequently, they may not accurately gauge preferences regarding the larger risks typically encountered in practice. To address this problem, the present paper develops more general, closed-form index measures of risk aversion and prudence that are applicable to either large or small risks. The new measures are exact in that they do not rely on approximations, they can be implemented empirically without knowledge of the functional form of utility, and they do not require information regarding pre-existing wealth.     

Self-enforcing contracts in agriculture

This article examines a self-enforcing contract between a risk-neutralprincipal and a risk-averse agent who is able to hold up valuesex post. It shows that risk aversion and variance can only partlyexplain the contract's incentive intensity. Ex post bargainingpower and outside options will also determine contract choice.If the agent's ex post bargaining position is weak, the principalcannot commit to high-powered incentives, whereas if the agent'sex post bargaining position is good, the agent cannot committo low-powered incentives. The model may thus explain some puzzlesin agricultural contracts, in particular why risk-averse agentssometimes accept to be governed by high-powered incentive contractsthat are quite similar to fixed rental contracts, and why risk-neutralagents are sometimes offered share contracts with lower-poweredincentives.     

低成本战略和新世纪中国石化工业的风险规避

随着亚太地区正逐渐成为新的全球能源消费中心，我国炼油、石化企业有较大的发展，我国的石油资源供需缺口和对外依存度正在逐年上升，由此带来的资源风险也在逐年提高。文章通过对国际油价变化的市场和政治因素的分析，提出了21世纪的中国石化工业在石油资源、能源消耗、氢资源利用以及资产投资等方面需要采取的低成本战略，以规避石化行业各种风险的到来，保障我国石化工业以致整个国民经济的健康发展。     

Relative risk aversion among the elderly

This paper examines portfolio allocation behavior of the elderly, investigating whether their behavior conforms to Arrow's postulate of increasing relative risk aversion. Additionally, the effects on risk aversion of age, race, gender, education, health status, and the number of children are examined. The source of data is the AHEAD data set that is comprised of households with at least one member aged 70 or over. In the preferred specification, evidence supports a finding of modestly decreasing relative risk aversion and statistical significance for the personal characteristics examined. Implications are drawn for the likely security markets effects of an aging population.     

A note on risk aversion and herd behavior in financial markets

We show that differences in market participants risk aversion can generate herd behavior in stock markets where assets are traded sequentially. This in turn prevents learning of market’s fundamentals. These results are obtained without introducing multidimensional uncertainty or transaction cost. JEL Classification G1 · G14 · C11 · D82     

Estimating Risk Attitudes in Denmark: A Field Experiment*

We estimate individual risk attitudes using controlled experiments in the field in Denmark. The experiments were carried out across Denmark using a representative sample of 253 people between 19 and 75 years of age. Risk attitudes are estimated for various individuals differentiated by socio‐demographic characteristics. Our results indicate that the average Dane is risk averse, and that risk neutrality is an inappropriate assumption to apply. We also find that risk attitudes vary significantly with respect to several important socio‐demographic variables such as age and education. However, we do not find any effect of sex on risk attitudes.