基于粗糙集-未确知测度的矿井通风系统合理性评价

运用粗糙集对矿井通风系统合理性评价指标体系进行约简,去除冗余指标,并求出约简指标体系中各指标的重要性,进行归一化后,作为未确知测度评价模型的指标权重系数。不仅减少了未确知测度评价的计算量,也为其权重确定问题提供了一种新的客观解决办法。同时,结合邯郸市峰峰矿区15个矿井的实测数据验证了该模型的有效性。     

Do foreign exchange forecasters apply asymmetric loss functions? Evidence from three major exchange rates

This article investigates which type of loss function is consistent with the hypothesis that major exchange rate forecasts, i.e. the euro, the British pound, and the Japanese yen vis-à-vis the US dollar, are rational. We apply a comprehensive data set, which also allows us to examine different forecast horizons and heterogeneity of forecasters.     

Do country risk and financial uncertainty matter for energy commodity futures?

Using an instrumental variable quantile regression technique, this paper assesses whether country risk and financial uncertainty exert an impact on energy commodity futures prices under different commodity conditional return distributions over the period from January 1994 to July 2017. We also discuss whether the correlations change with different dimensions of country risk, that is economic, financial, and political. The results reveal that country risk and financial stress do have a significant impact on energy commodity returns of futures contracts with different maturities, but their direction, intensity, and significance differ, caused by the distinct market situations and divergent channels of country risk.     

Individually rational rules for the division problem when the number of units to be allotted is endogenous

We study individually rational rules to be used to allot, among a group of agents, a perfectly divisible good that is freely available only in whole units. A rule is individually rational if, at each preference profile, each agent finds that her allotment is at least as good as any whole unit of the good. We study and characterize two individually rational and efficient families of rules, whenever agents' preferences are symmetric single-peaked on the set of possible allotments. Rules in the two families are in addition envy-free, but they differ on whether envy-freeness is considered on losses or on awards. Our main result states that (a) the family of constrained equal losses rules coincides with the class of all individually rational and efficient rules that satisfy justified envy-freeness on losses and (b) the family of constrained equal awards rules coincides with the class of all individually rational and efficient rules that satisfy envy-freeness on awards.     

Intertemporal substitution in the Spanish economy: Evidence from regional data

This paper studies the intertemporal substitution in consumption and leisure for the Spanish economy by estimating the first‐order conditions of an individual optimization model with regional and aggregate data. While first‐order conditions determining intertemporal substitution in consumption show a good econometric fit, and the value we obtain for the intertemporal elasticity of substitution is similar to previously available results, the econometric fit of the intertemporal condition in leisure indicates that the behaviour of the Spanish labour supply over the cycle is more complex than can be explained by the canonical intertemporal choice model.     

Monetary policy,doubts and asset prices

Asset prices and the equity premium might reflect doubts and pessimism. Introducing these features in an otherwise standard New-Keynesian model changes optimal policy in a substantial way. There are three main results: (i) asset-price movements improve the inflation-output trade-off so that average output can rise without much inflation costs; (ii) a “paternalistic” policymaker – maximizing the expected utility of the consumers under the true probability distribution – chooses a more accommodating policy towards productivity shocks and inflates the equity premium; (iii) a “benevolent” policymaker – maximizing the objective through which decisionmakers act in their ambiguous world – follows a policy of price stability.     

Revealed preferences of individual players in sequential games

This paper studies rational choice behavior of a player in sequential games of perfect and complete information without an assumption that the other players who join the same games are rational. The model of individually rational choice is defined through a decomposition of the behavioral norm assumed in the subgame perfect equilibria, and we propose a set of axioms on collective choice behavior that characterize the individual rationality obtained as such. As the choice of subgame perfect equilibrium paths is a special case where all players involved in the choice environment are each individually rational, the paper offers testable characterizations of both individual rationality and collective rationality in sequential games.     

中国国情下的保险费率监管模式选择及影响分析--来自车险市场的经验证据

我国保险监管朝着“放开前端、管住后端”的模式发展,保险费率市场化改革的呼声始终较高。文章以财险市场中市场份额最大的车险为研究对象,基于2001－2014年样本分析了费率市场化与费率水平合理性之间的关系。研究发现,我国车险市场的实际费率水平明显低于理论费率;费率监管的严格程度的确会影响费率水平的合理性,其中适度监管模式下的费率水平最为合理。文章进一步深入探究了费率水平合理性对偿付能力的影响机制,发现费率差异的波动性会通过净利润而间接影响偿付能力。费率差异的波动性越小,净利润越高,偿付能力越强,因此应慎重选择费率监管制度。文章建议我国保险市场应采用适度监管的费率制度,完全放开的费率市场化略显激进,不适合当前国情。这样不仅能使费率水平更加合理,还不会威胁保险公司的偿付能力,从而使保险市场更加健康稳步的发展。     

The Refined Best Reply Correspondence and Backward Induction

Fixed points of the (most) refined best reply correspondence, introduced in Balkenborg et al. (2013), in the agent normal form of extensive form games with perfect recall have a remarkable property. They induce fixed points of the same correspondence in the agent normal form of every subgame. Furthermore, in a well‐defined sense, fixed points of this correspondence refine even trembling hand perfect equilibria, while, on the other hand, reasonable equilibria that are not weak perfect Bayesian equilibria are fixed points of this correspondence.     

旅游学方法论：何来“主义”之争？——与宋子千、张斌等人商榷

宋子千的《旅游研究方法论的实证主义与现象学之争》（简称《之争》）一文将申葆嘉先生的“旅游是市场经济的产物”和谢彦君教授的“旅游的本质是体验”分别作为旅游学研究中实证主义和现象学方法的代表性观点而对立起来。实际上, 不管是在当代旅游学界, 还是在申、谢两位学者之间, 都不存在关于研究方法论的“主义”之争一说。《之争》在未考虑科学研究中不同类型的问题需要不同的方法的情况下对两位学者的立场做出了武断的批评, 如果不予以澄清, 很可能会引起学术界在此类问题上的无谓甚至错误的争论, 误导学术研究的方向。同时, 《之争》在现象学的分析和技术理性等概念的使用上还有诸多值得商榷之处, 另有若干细节问题亦需要进一步澄清。鉴于旅游学在我国的发展还处于较为初步的阶段, 对旅游学基础理论的讨论必须秉持客观、严谨和科学的态度, 该文旨在与《之争》中的若干观点做一些商榷性的讨论。