Do People Move When They Say They Will? Inconsistencies in Individual Migration Behavior

Conventional theories of migration decision–making posit that there exists a simple, sequential link between residential satisfaction, mobility intentions and actual moving behavior. Past empirical work, however, has indicated substantial discrepancies between mobility intentions and behavior. This study investigates behavioral inconsistencies in migration using data drawn from the 1985, 1987 and 1989 rounds of the American Housing Survey (AHS). Mobility is inferred by comparing occupants of the same housing units in two consecutive surveys. The results show that a substantial number of people do not realize their intention to move and many move unexpectedly; with or without prior intentions to move, movers and stayers appear to differ significantly in terms of their sociodemographic characteristics. The extent to which individuals act consistently with their intentions also differs along with their attributes (e.g., tenure, age, education and gender). The paper discusses possible reasons for behavioral inconsistencies in migration based on recent developments in social psychological theories of human behavior.     

逻辑的观念与理论——中国逻辑史研究的两个重要因素

“中国历史上是否存在逻辑学”是国内逻辑学界长期争论的问题。其中,“没有逻辑”说还分为绝对论者和相对论者:绝对论者认为中国古代没有任何形式的逻辑;相对论者认为中国古代虽然没有西方意义上的逻辑,但只有非形式逻辑。之所以学者们在此问题上争论不休,是由于双方对什么是逻辑有不同的理解。在进行中西逻辑学比较之前,首先要确定一种统一的逻辑观念,因为逻辑观念是逻辑理论得以形成的基础。     

论计划生育村民自治

建立健全“依法管理、村(居)民自治、优质服务、政策推动、综合治理”的长效工作机制,是《中共中央国务院关于全面加强人口和计划生育工作统筹解决人口问题的决定》(2006)对我国未来计划生育管理提出的基本要求,也是全国部分地区在人口和计划生育综合改革实践中探索出的一条基本经验。然而,对长效工作机制中的“村民自治”,人们在认识上还存在一些误区,从而导致了工作实践中的一些偏差。本文拟就计划生育村民自治中的几个基本问题谈点意见。1计划生育村民自治的概念村民自治是我国广大人民群众直接行使民主权利的一项基本社会政治制度。“计…     

金融发展与贸易依存度的实证研究——基于东部十省市面板数据的协整分析

本文利用东部十省市的面板数据,研究金融发展与贸易依存度的关系。运用面板单位根检验和面板协整检验,建立面板协整模型进行分析。结果显示：金融发展仅与进口依存度存在长期均衡关系,且不同省市金融发展对进口依存度的推动作用不同。最后分析其作用差异的潜在原因,并根据实证结果提出了政策建议。     

Evaluation of multilevel decision trees

The evaluation of decision trees under uncertainty is difficult because of the required nested operations of maximizing and averaging. Pure maximizing (for deterministic decision trees) or pure averaging (for probability trees) are both relatively simple because the maximum of a maximum is a maximum, and the average of an average is an average. But when the two operators are mixed, no simplification is possible, and one must evaluate the maximization and averaging operations in a nested fashion, following the structure of the tree. Nested evaluation requires large sample sizes (for data collection) or long computation times (for simulations).     

互连网络拓扑优化设计

论述了互连网络拓扑优化设计问题,建立了必要的数学模型,该数学模型是一个非线性组合优化问题,它属于NP—完备类问题。采取拉格朗日松弛法、次梯度迭代算法和启发式算法,得出最优下确界和结论。     

坩埚热导率对晶体生长温度场的影响

本文通过有限元数值方法计算了坩埚热导率对晶体生长温度场的影响,指出当坩埚热导率大于晶体材料的热导率时,生长区域的纵向温梯会有大幅度减小,反之,温梯变化较小。并且认为当坩埚侧面与环境的热交换系数很大时,坩埚热导率的影响作用变小。并指出坩埚热导率可以通过热处理及其他手段予以调节。     

论统计理论研究方法体系

一、统计理论研究方法体系的提出　　在相当长的一段时间里,我国统计界在进行统计理论研究时虽有意无意地采用了一些研究方法,但是,这些研究方法基本上分散零乱的,没使之系统化,这也许是造成我国统计理论研究还比较落后的一个重要原因。随着市场经济的不断完善,统计理论研究的不断深入,人们发现我国统计理论研究在向新领域、新高度跨越时,现有的方法难以适应研究的需要,客观实际方面要求我们应不断地总结过去的研究方法,创建新的研究方法。因此,对统计理论研究方法本身的研究被提到议事日程。实际上,当今科学技术的飞跃进步,科…     

Weighted local linear composite quantile estimation for the case of general error distributions

It is known that for nonparametric regression, local linear composite quantile regression (local linear CQR) is a more competitive technique than classical local linear regression since it can significantly improve estimation efficiency under a class of non-normal and symmetric error distributions. However, this method only applies to symmetric errors because, without symmetric condition, the estimation bias is non-negligible and therefore the resulting estimator is inconsistent. In this paper, we propose a weighted local linear CQR method for general error conditions. This method applies to both symmetric and asymmetric random errors. Because of the use of weights, the estimation bias is eliminated asymptotically and the asymptotic normality is established. Furthermore, by minimizing asymptotic variance, the optimal weights are computed and consequently the optimal estimate (the most efficient estimate) is obtained. By comparing relative efficiency theoretically or numerically, we can ensure that the new estimation outperforms the local linear CQR estimation. Finite sample behaviors conducted by simulation studies further illustrate the theoretical findings.