An IV Model of Quantile Treatment Effects

The ability of quantile regression models to characterize the heterogeneous impact of variables on different points of an outcome distribution makes them appealing in many economic applications. However, in observational studies, the variables of interest (e.g., education, prices) are often endogenous, making conventional quantile regression inconsistent and hence inappropriate for recovering the causal effects of these variables on the quantiles of economic outcomes. In order to address this problem, we develop a model of quantile treatment effects (QTE) in the presence of endogeneity and obtain conditions for identification of the QTE without functional form assumptions. The principal feature of the model is the imposition of conditions that restrict the evolution of ranks across treatment states. This feature allows us to overcome the endogeneity problem and recover the true QTE through the use of instrumental variables. The proposed model can also be equivalently viewed as a structural simultaneous equation model with nonadditive errors, where QTE can be interpreted as the structural quantile effects (SQE).     

Bounded influence nonlinear signed‐rank regression

In this paper we consider weighted generalized‐signed‐rank estimators of nonlinear regression coefficients. The generalization allows us to include popular estimators such as the least squares and least absolute deviations estimators but by itself does not give bounded influence estimators. Adding weights results in estimators with bounded influence function. We establish conditions needed for the consistency and asymptotic normality of the proposed estimator and discuss how weight functions can be chosen to achieve bounded influence function of the estimator. Real life examples and Monte Carlo simulation experiments demonstrate the robustness and efficiency of the proposed estimator. An example shows that the weighted signed‐rank estimator can be useful to detect outliers in nonlinear regression. The Canadian Journal of Statistics 40: 172–189; 2012 © 2012 Statistical Society of Canada     

免费师范生教育政策过程中的政策利益分析——基于有限理性利益人的视角

从有限理性利益人的视角,通过对免费师范生教育政策过程中各方政策利益相关者的政策利益的解析可以看出其中可能存在的政策利益变化。政策主体需要明确政策利益相关者的存在,解析政策利益及其变化,完善政策方案设计与配套措施,建立免费师范生教育政策的退出机制和问责机制,才能保障免费师范生教育政策的有效实施。     

基于有限理性消费者的竞争性退款保证策略

考虑有限理性消费者的前提下研究了低质和高质零售商关于退款保证的策略竞争。进一步将模型扩展到存在产品质量差异的情形,研究产品质量对双方策略的影响。研究表明:只有当有限理性消费者数量高于一定临界值时,提供退款保证才是有利可图的。在产品质量对称的市场上,零售商关于退款保证的均衡局面为同时提供退款保证,且此时退款保证对低质企业更有利;而在产品质量非对称的市场上,零售商关于退款保证的均衡局面可能为低质企业不提供,高质企业提供或双方同时提供。此时退款保证更倾向于对高质企业有利。     

基于有限合作机制的群决策熵模型研究

研究一类具有合作机制的群决策问题。提出两阈值的合作函数对决策人之间的合作关系进行模糊分类,采用模糊测度方法度量决策人和决策人集的权力指数,建立合作群决策的非线性规划熵模型集结权力指数,并基于极大熵的最优化原理求解该模型。利用Choquet模糊积分计算备选方案的综合评价值,并对备选方案排序选择最优方案。最后通过算例分析并验证合作群决策模型和运用模糊积分方法求解模型的合理性、有效性。     

“统统”句的语法语义考察

统统句中的谓语成分一般不能是单个动词。统统句不但要求谓语是有界的表达,而且一般也要求被全称量化的NP都是一个有指的、定指的成分。从语义上来说,不是所有的动词都可以出现在统统之后作谓语,出现在统统之后的谓语动词常常是有消极语义的、大家不希望发生的词语,也有一部分是中性语义的词语,很少有积极意义的动词出现在统统后作谓词性成分。统统和其他修饰语共现时的顺序也各不相同。     

Impulse Balance and Multiple‐Period Feedback in the Newsvendor Game

Human subjects in the newsvendor game place suboptimal orders: orders are typically between the expected profit‐maximizing quantity and mean demand (“pull‐to‐center bias”). In previous work, we have shown that impulse balance equilibrium (IBE), which is based on a simple ex post rationality principle along with an equilibrium condition, can predict ordering decisions in the laboratory. In this study, we extend IBE to standing orders and multiple‐period feedback and show that it predicts—in line with previous findings—that constraining newsvendors to make a standing order for a sequence of periods moves the average of submitted orders toward the optimum.     

基于Mealy自动机的多人重复博弈演化模型及仿真分析

本文提出一种基于Mealy自动机的多人重复博弈演化模型。该模型用Mealy自动机表示博弈参与人的战略行为,并构造一个基于遗传算法的自动机演化程序。博弈初始时,博弈参与人提交一个Mealy自动机。博弈参与人的有限自动机在当前状态下与竞争对手的自动机进行博弈,并且依据其获取的支付转换到下一状态,然后在新的状态下开始新一周期的博弈。在进行一段时间博弈后,则利用自动机演化程序对自动机进行演化,演化的标准是依据其在这一段时间博弈中的获得的平均支付及战略成本。通过仿真可以验证,在参与人理性程度较低且存在信息干扰的情况下,博弈参与人为了降低在博弈过程中的信息失真率,战略成本需要以较大的幅度下降。     

An enhanced BAM for unbounded or partially bounded CRS additive models

The Bounded Adjusted Measure (BAM), initially defined for the additive model, which is a variable returns to scale (VRS) model, was extended to the constant returns to scale (CRS) case [7]. The added range-bounds, which maintain unaltered the production possibility set (PPS) under VRS, showed an influential effect under CRS, reducing the corresponding PPS, as well as a negative effect, excluding some of the original CRS projections. Here we propose an enhanced extension that, by considering a different set of less restrictive bounds, eliminates the negative effect. Moreover, we customize this new extension for the family of partially bounded CRS additive models, i.e., models where at least one variable is naturally bounded from below, if it is an input, or from above, if it is an output.     

内容平实 寓意深长——对大学英语课文《The Day Mother Cried》主题意义的思考

信念是激励人积极行动、克服困难的重要动力。人们对自己行动的认识越明确、越深刻 ,克服困难、坚持到底的意志力就越强大。人世间没有什么能超越信念的力量。只要目标确定 ,凝聚人生的全部合力 ,所有坚韧不拔的努力迟早会得到回报的