Time preferences and risk aversion: Tests on domain differences

Understanding how individuals discount and evaluate the risks of environmental outcomes is a prime component in designing effective environmental policy. We use an incentivized experimental design to investigate whether subjects’ time preferences and risk aversion across the monetary and environmental domains differ. We find that subjects’ time preferences are not significantly different across the two domains. In contrast, subjects exhibit a higher degree of risk aversion in the environmental domain. Furthermore, we corroborate earlier results, documenting that women are more risk averse than men in the monetary domain, and show this finding to also hold in the environmental domain.     

时间概念的历史与被叙述的时间

很少有人从时间观的变化概括哲学思考的历史,但事实上,哲学史也是时间概念变化的历史,而这种变化,最明显地体现在文本书写形式的变化,即一切叙述都是关于时间的叙述,是以时态或不同类型的语句之间的各种连接形式构成的。一般来说,在哲学领域,时间概念的历史有两条基本的线索:其一是以亚里士多德为代表的,强调时间是世界的运动形式而不是心理的活动方式;另外一条线索,也就是本文着重分析的,是从奥古斯丁、胡塞尔、海德格尔到普鲁斯特,强调时间是“精神”的某种膨胀和收缩,与世界上正在运动着的某样东西无关。整个20世纪的欧洲哲学与文学艺术运动的主流,都与第二条线索有密切关系。至于康德的时间观,则属于这两条线索之间的中间派。本文特别把以上提到的两条时间线索,分别称为“纵向的时间观”与“横向的时间观”,前者从时间之外的对象中获得时间的解释,后者则是一种非对象化的时间概念,或者称为“彼在”、“异域”。     

Lifetime Uncertainty and Time Preference

Despite Fisher's (1930) psychological intuitions of and the formal treatment given by Yaari (1965, Review of Economic Studies 32, 137), the intertemporal model of choice is mainly a model with certain lifetime. The purpose of this paper is to reconsider this assumption, starting from a very simple two-period model of choice with lifetime uncertainty. We examine the comparative statics of the model at the first two orders and replace the concept of `pure time preference' by taking into account the subjective treatment of the probability of survival. This revised version was published online in June 2006 with corrections to the Cover Date.     

Time preferences and consumer behavior

We investigate the predictive power of survey-elicited time preferences. The discount factor elicited from choice experiments using real payments predicts various health, energy, and financial outcomes, including overall self-reported health, smoking, installing energy-efficient lighting, and credit card balance. Allowing for time-inconsistent preferences, both the long-run and present-bias discount factors (δ and β) are also significantly associated in the expected direction with several outcomes. We consider several hypotheses regarding the strength of the association between discount factors and outcomes, such as salience of the outcome or liquidity constraints.     

雕刻时光——钟表制造漫谈

正世界上第一座以嘀嗒嘀嗒的机械擒纵机构为标记的时钟,相传是出现在中国的宋代,由苏颂组织创制的水运仪象台,于13世纪传入欧洲。古老的塔钟,十五分钟一响,对比中国古时的时辰制计时,成了一种田园牧歌式的写意化表达。今天,手执一只机械名表,我们津津乐道于它的品牌形象、陀飞轮技术,三问报时功能,还有月相、深水抗压,或者是嵌珠     

基于时间学的思想政治教育时间规律新探

随着即时网络时代的到来,思想政治教育学要实现现代转型,探究者必须紧跟时代行进的步履,发扬探赜索隐、钩深致远的精神,深入揭示和科学应用思想政治教育新规律尤其是时间规律。基于时间学,从社会背景条件、教育对象、教育者、管理者角度去考察,思想政治教育时间规律群大致包括思想政治教育一定要适合时代发展状况规律、思想政治品德形成发展的时间规律、对人们进行思想政治教育的时间规律和思想政治教育时间管理规律等四大类型的一级时间规律。其中,每一类型的一级规律包含诸多二级规律或曰子规律。自觉把握和科学应用这些规律,有助于推动思想政治教育不断从实然状态向应然状态、从必然王国向自由王国飞跃。     

Preference reversals: Time and again

This paper sheds new light on the preference reversal phenomenon by analyzing decision times in the choice task. In a first experiment, we replicated the standard reversal pattern and found that choices associated with reversals take significantly longer than non-reversals, and non-reversal choices take longer whenever long-shot lotteries are selected. These results can be explained by a combination of noisy lottery evaluations (imprecise preferences) and an overpricing phenomenon associated with the compatibility hypothesis. The first cause explains the existence of reversals, while the second explains the predominance of a particular type thereof. A second experiment showed that the overpricing phenomenon can be shut down, greatly reducing reversals, by using ranking-based, ordinally-framed evaluation tasks. This experiment also disentangled the two determinants of reversals, because imprecise evaluations still deliver testable predictions on decision times even in the absence of the overpricing phenomenon. Strikingly, when unframed ranking tasks were used, decision times in the choice phase were greatly reduced, even though this phase was identical across treatments. This observation is consistent with psychological insights on conflicting decision processes.     

欢乐友谊的瞬间——记中国医科大学留学生新年联欢会

2006年12月31日中国医科大学的体育馆内洋溢着欢乐的节日气氛。留学生辞旧迎新的新年联欢会在这里如期举行。来自世界各地近30个国家的200多名留学生与来自港、澳、台地区和其他国家和地区的华侨学生及部分在校的中国学生100多人欢聚一堂,共同庆祝这个欢乐时刻。     

胡塞尔的内在时间意识与西方哲学的时间观

时间问题是西方哲学最艰深的也是最重要的问题之一 ,从柏拉图到胡塞尔相继出现了实体论时间观、关系论时间观、个人主观时间观、先验时间观和内在时间意识 ,胡塞尔上承奥古斯丁而持内在时间意识观念 ,既别于牛顿的时间客观实体论 ,又别于心理主义的个人主观时间论。本文把胡塞尔的内在时间意识学说置于西方时间学说发展的历史背景中 ,努力阐明其与各种时间观的理论因承关系及异同点 ,以此来阐述其内在时间意识的内涵及意义。     

收藏，恰逢其时

越危机越保值 对经济危机、金融海啸这些近期频频在各种场合出现的令人心惊肉跳的名词,更多地看到它们的正面效应--些不同国家和地区,不同文化背景、不同工作性质的文化艺术市场一线人物为当下处于低迷的艺术品市场诠解了一番颠覆的论调.     

Economic consequences of Nth-degree risk increases and Nth-degree risk attitudes

We study comparative statics of Nth-degree risk increases within a large class of problems that involve bidimensional payoffs and additive or multiplicative risks. We establish necessary and sufficient conditions for unambiguous impact of Nth-degree risk increases on optimal decision making. We develop a simple and intuitive approach to interpret these conditions : novel notions of directional Nth-degree risk aversion that are characterized via preferences over lotteries.     

《老子》的作者及其成书时代

<老子>非一人一时一地写成,而是经过后学多次补充、加工、阐释、整理而成.<老子>最初由老聃口述大义,其后学整理成最早的传本,老莱子和太史儋是<老子>在流传过程中的整理和再次加工阐释者.<老子>初稿成于春秋末期,最后写定在战国末年或汉初.李耳是汉代人对老聃的另一种称谓.     

时间与海德格尔的“时间性”

本文不是试图对海德格尔进行解释 ,而是试图从文本本身的角度质疑《存在与时间》中概念的矛盾性。《存在与时间》建立了一种新的 ,关于时间始源性问题的学说。时间的始源 ,被海德格尔称为“时间性”。时间性在此在分析中有中心地位 ,对时间作出了新的解释。然而时间性本身却是一个矛盾概念。时间性源于死的本真性 ;死所以是最本真的 ,因为死是必须此在自己去承担的存在可能性。如果以是否自己去承担为标准 ,那么此在能承担的存在可能性并不只有死。所以死不可能是最本真的。因而 ,时间性也不可能是始源性的时间学说。文章通过对时间性的分析指出 ,时间性学说是建立在对于时间的一般理解之上的。     

Decreasing absolute risk aversion, prudence and increased downside risk aversion

Downside risk increases have previously been characterized as changes preferred by all decision makers u(x) with u????(x) > 0. For risk averse decision makers, u????(x) > 0 also defines prudence. This paper finds that downside risk increases can also be characterized as changes preferred by all decision makers displaying decreasing absolute risk aversion (DARA) since those changes involve random variables that have equal means. Building on these findings, the paper proposes using ??more decreasingly absolute risk averse?? or ??more prudent?? as alternative definitions of increased downside risk aversion. These alternative definitions generate a transitive ordering, while the existing definition based on a transformation function with a positive third derivative does not. Other properties of the new definitions of increased downside risk aversion are also presented.     

Baseline risk and marginal willingness to pay for health risk reduction

Empirical results presented in this paper suggest that parents’ marginal willingness to pay (MWTP) for a reduction in morbidity risk from heart disease is inversely related to baseline risk (i.e., the amount of risk initially faced) both for themselves and for their children. For instance, a 40% reduction from the mean of baseline risk results in an increase in MWTP by 70% or more. Thus, estimates of monetary benefits of public programs to reduce heart disease risk would be understated if the standard practice is followed of evaluating MWTP at initial risk levels and then multiplying this value by the number of cases avoided. Estimates are supported by: (1) unique quantitative information on perceptions of the risk of getting heart disease that allow baseline risk to be defined at an individual level and (2) improved econometric procedures to control for well-known difficulties associated with stated preference data.     

时间之窗与时间之创——留守经历对主观幸福感影响的时间效应

本文从生命历程视角出发,基于 2018 年“中国劳动力动态调查”数据,从累积留守时长、结束留守时长、留守阶段、留守时监护类型等维度分析了童年期留守经历对个体成年后主观幸福感的影响。 研究发现,留守经历对个体主观幸福感有长期负面影响,并具有“双重时间效应”：累积留守时间越长,对留守者成年后主观幸福感造成的负面冲击越大, 且留守者成年后主观幸福感并不会因结束留守时长的增加而回升; 留守经历对个体主观幸福感的负面影响呈现“初中留守＜小学留守＜学前留守”的逆向递增特点,即学前阶段是影响个体主观幸福感的“关键窗口”;无论是哪个阶段,单亲监护和祖辈监护都会对个体主观幸福感产生负面影响,且呈现“单亲监护>祖辈监护>双亲监护”的特点。     

Free Time Under Communism

With the reduction of the working day increasing attention has been focused on the use of leisure time. This article points to the major activities which will occupy people's free time in the communist society of the future. ["Free Time Under Communism—Answers to Questions," Voprosy Filosofii, 1960, No. 5—abridged.]     

自由闲逸的超完美时光流连市南不知厌

青岛是一座梦幻浪漫的滨海旅游城市,是向往超完美时光的所有驴友最心仪的地方之一.位于青岛前海一线、一边碧海一边美城的市南区,是一座风姿绰约的“海上花园”,这里是青岛之行梦开始的地方.     

《哈利·波特》:10年一觉魔法梦

十年前,大银幕上那个戴着破旧眼镜的小男孩,接到了雪花般的霍格沃茨的录取通知书,从此一个全新的魔法世界的大门向他打开了,也向全世界麻瓜打开了,我们跟随着他推着海德薇和巨大的行李,闭着眼睛穿过九又四分之三站台,认识了坐在车厢里努力吃着魔法零食的傻小子罗恩,还发现了一个满头乱发、趾高气扬但是却帮哈利修好了眼镜的小女孩赫敏。