宣州基层避孕方法知情选择工作浅析

基于对安徽省宣州市几个乡镇的走访调查 ,概述了当地避孕方法知情选择工作开展现状和取得的初步成效 ,简要分析了存在的问题并提出相应改进建议     

A Theory of Rational Choice under Ignorance

This paper contributes to a theory of rational choice for decision-makers with incomplete preferences due to partial ignorance, whose beliefs are representable as sets of acceptable priors. We focus on the limiting case of `Complete Ignorance' which can be viewed as reduced form of the general case of partial ignorance. Rationality is conceptualized in terms of a `Principle of Preference-Basedness', according to which rational choice should be isomorphic to asserted preference. The main result characterizes axiomatically a new choice-rule called `Simultaneous Expected Utility Maximization'. It can be interpreted as agreement in a bargaining game (Kalai-Smorodinsky solution) whose players correspond to the (extremal) `acceptable priors' among which the decision maker has suspended judgment. An essential but non-standard feature of Simultaneous Expected Utility choices is their dependence on the entire choice set. This is justified by the conception of optimality as compromise rather than as superiority in pairwise comparisons.     

Choice Functions: Rationality re-Examined

On analyzing the problem that arises whenever the set of maximal elements is large, and a selection is then required (see Peris & Subiza 1998), we realize that logical ways of selecting among maximals violate the classical notion and axioms of rationality. We arrive at the same conclusion if we analyze solutions to the problem of choosing from a tournament (where maximal elements do not necessarily exist). So, in our opinion the notion of rationality must be discussed, not only in the traditional sense of external conditions (Sen 1993), but in terms of the internal information provided by the binary relation.     

持股周期与股票盈利:来自中国A股市场的证据

价值投资是格雷厄姆经典投资理论的基本特征之一,坚持价值投资是投资者在股市中盈利的前提,但现实中我国投资者亏多赢少,可能的原因是投机心理导致的非理性行为。我国个人投资者持股周期普遍较短这一重要特征为该问题的研究提供了检验。本文基于我国股票市场个人投资者的微观调查数据,研究了个人投资者的持股周期对其股票盈利的影响,研究结果表明:与其他投资者相比,平均持股周期短的投资者在股市中更难盈利。可能的影响机制是持股周期短的投资者投资组合的多元化程度不足,导致盈利的可能性较低。异质性分析表明,前述作用机制在投资经验欠缺、可投资资产不足、跟风操作的投资者群体中表现得更为明显。本文的研究结论为个人投资者坚持长期投资和价值投资理念提供了经验证据。     

Data-Driven Model Choice in Multivariate Nonparametric Regression

The problem of choosing between different regression models, is investigated. A completely automatic model selection procedure is defined and asymptotic optimality results are shown. These results are stated in a general framework including as well nested as unnested situations, including as well i.i.d. as dependent samples, and without specifying any class of non-parametric smoothers. Because of the well-known curse of dimensionality, model selection is of particular interest in multivariate regression settings, and it will be discussed how the previous general model choice approach can be used in several different highdimensional situations.     

Behavioral implications of providing real incentives in stated choice experiments

This paper explores the potential impacts of introducing real economic incentives in choice experiments (CE). While many others have investigated such impacts before, the majority of the literature has focused solely on mitigation of hypothetical bias. We contribute to this literature by widening the scope of research to other behavioral aspects where consumers in CE are often found to deviate from homo economicus. We develop a theoretical model where not only Willingness to pay (WTP) measures but also decision processing can be affected by the introduction of an economic incentive. Specifically, our model allows for differential impacts on attribute processing, depending on the character of the attribute as well as self-image effects. In an empirical CE survey, we find some, though not unequivocal, support of our model. Even though we find no impact on WTP from introducing an economic incentive, we find marked benefits in relation to a number of behavioral aspects that together would favor the use of an economic incentive regardless of hypothetical bias being present or not.     

Choice set,relative income,and inequity aversion: An experimental investigation

Inequity aversion preference has been widely applied in interpretations of various economic behaviors. A rapidly growing literature has been attempting to measure the strength of inequity aversion preferences as accurately as possible. We vary two factors that might affect the accuracy of the measurement of inequity aversion preference, i.e., choice sets with different underlying inequity aversion strength ranges and with different relative income inequities while absolute income inequities remain fixed. We find that unidirectional changes in the choice sets for disadvantageous and advantageous inequity aversion preferences significantly bias the measured strength of both preferences in the same directions of the changes and that the variance in inequity aversion increases with the range of choice sets. Moreover, a decrease in relative income inequity raises the measured strength of advantageous inequity aversion but does not affect disadvantageous inequity aversion preference. Our results suggest controlling for choice sets and relative income inequity between players to improve the measurement accuracy of inequity aversion preference.     

Effect of choice complexity on design efficiency in conjoint choice experiments

Conjoint choice experiments have become a powerful tool to explore individual preferences. The consistency of respondents' choices depends on the choice complexity. For example, it is easier to make a choice between two alternatives with few attributes than between five alternatives with several attributes. In the latter case it will be much harder to choose the preferred alternative which is reflected in a higher response error. Several authors have dealt with this choice complexity in the estimation stage but very little attention has been paid to set up designs that take this complexity into account. The core issue of this paper is to find out whether it is worthwhile to take this complexity into account in the design stage. We construct efficient semi-Bayesian D-optimal designs for the heteroscedastic conditional logit model which is used to model the across respondent variability that occurs due to the choice complexity. The degree of complexity is measured by the entropy, as suggested by Swait and Adamowicz (2001). The proposed designs are compared with a semi-Bayesian D-optimal design constructed without taking the complexity into account. The simulation study shows that it is much better to take the choice complexity into account when constructing conjoint choice experiments.     

论近代英法国家的税收与政体选择——基于交易费用的视角

税收不仅有助于现代国家的诞生，更是现代国家发展的强大推动力量。在政府与纳税人漫长的税收博弈过程中，政府会通过各种手段提高自己的相对讨价还价权力，但面临着竞争约束和交易费用约束。为了获得更多的税收收入，政府必须采取相应措施降低交易费用。而不同性质的税收在征收过程中面临的交易费用是不同的，这会对国家的政体选择和政治发展产生不同影响，英国和法国提供了历史的经验证明。     

An Ethical Interpretation of the Nash Choice Rule

This paper provides an ethical intepretation of the Nash choice rule. In a setting in which (cardinal) utilities are interpersonally comparable, this procedure is characterised by an impartiality requirement and by the assumption that choices are not responsive to the agents' relative ability to convert resources into utility.