救助、就业与福利依赖——兼论关于中国低保制度“养懒汉”的担忧

西方关于福利依赖及其对就业的负面影响的讨论从1980年起成为热点,主流观点认为救助对于贫富差距的调节作用有限,且可能造成福利依赖,不利于就业甚至影响经济发展。受其影响,近年来中国学界和公共平台也出现了关于低保这项救助制度"养懒汉"的担忧。文章通过回顾国内外现有的理论和经验研究,分析了救助是否必然导致福利依赖、就业是否能避免福利依赖以及中国的低保制度是否存在"养懒汉"问题这三个议题,提出救助、就业和福利依赖的关系是复杂的,它并非通常认为的"救助会导致福利依赖,而就业能避免福利依赖"。救助和就业并非"对立"或简单的替代关系,应从"协调"的角度来重新认识二者关系。     

Coherent Frequentism: A Decision Theory Based on Confidence Sets

By representing fair betting odds according to one or more pairs of confidence set estimators, dual parameter distributions called confidence posteriors secure the coherence of actions without any prior distribution. This theory reduces to the maximization of expected utility when the pair of posteriors is induced by an exact or approximate confidence set estimator or when a reduction rule is applied to the pair. Unlike the p-value, the confidence posterior probability of an interval hypothesis is suitable as an estimator of the indicator of hypothesis truth since it converges to 1 if the hypothesis is true or to 0 otherwise.     

Amemiya‘s generalized least squares and tests of overidentification in simultaneous equation models with qualitative or limited dependent variables

Amemiya's generalized least squares method for the estimation of simultaneous equation modeis with qualitative or limited dependent variables is known to be efficient relative to many popular two stage estimators. This note points out that test statistics for overidentification restrictions can be obtained as by-products of Amerniya's generalized least squares procedure. Amemiya's procedure is shown to be a minimum chisquare method. The Amemiya procedure is valuable both for efficient estimation and for model evaluation of such models.     

Normal theory sample size formulas for some nonnormal distributions

Sample size procedures of T- and F-tests for some nonnormal distributions are discussed. An adaptation to the Kruskal-Wallis and Friedman tests is mentioned.     

Number of Replications Required in Control Chart Monte Carlo Simulation Studies

Monte Carlo simulations have been used extensively in studying the performance of control charts. Researchers have used various numbers of replications in their studies, but almost none of them provided justifications for the number of replications used. Currently, there are no empirically based recommendations regarding the required number of replications to ensure accurate results. This research examined six recently published studies to develop recommendations for the minimum number of replications necessary to reproduce the reported results within a specified degree of accuracy. The results of this study indicated that using 10,000 replications was unnecessarily large and a smaller number of replications could be used to reproduce the target ARLs within the 2% error bands satisfying the modified Mundfrom's criteria. In many cases, only 5,000 replications or fewer were required. In general, the number of replications required to reproduce the target ARL decreased as the shift size increased. In addition, the results of this study provide general recommendations for the required number of replications to use in future SPC simulation studies.     

最低工资政策的城镇家庭收入分配效应研究

家庭在福利分析中具有重要地位，但家庭收入如何受最低工资政策影响却很少得到关注。本文采用2005-2015年中国综合社会调查（CGSS）数据，利用多时期双重差分和再中心化影响函数回归方法实证考察了最低工资政策对我国城镇家庭收入及其分布的影响。研究发现：①最低工资标准上涨显著提升了处于贫困标准1~2倍家庭的收入水平，对贫困标准以下或高于贫困标准2倍以上的家庭收入没有影响；②最低工资标准提升可有效减缓城镇家庭收入不平等，尤其对家庭收入分布较低分位部分的不平等程度有明显改善；③最低工资政策对家庭收入的最终影响取决于工资溢出效应和就业挤出效应的比较，且其对不同收入等级家庭中成员的收入和就业影响存在明显的异质性。政府在制定最低工资政策时，应针对低收入女性劳动力出台相应的配套措施，以保证各类低收入家庭均能从最低工资标准提升中受益。     

Non-parametric estimation of the long-range dependence exponent for Gaussian processes

We consider a class of long-range-dependent Gaussian processes defined in a semiparametric framework. We propose a new estimator of the long-range dependence parameter, based on the integration of the periodogram in two windows. We show that it is asymptotically Gaussian and calculate the rate of convergence. We optimise parameters defining the window function for the minimum mean-square-error criterion. In a Monte-Carlo study, we compare the proposed estimator with previously studied estimators.     

从收入分配和经济发展的角度看我国的最低工资制度

本文基于我国的一些特殊的国情,从动态的视角出发,讨论了最低工资制度对我国收入分配格局和经济发展的影响.本文研究认为,由于我国特殊的国情,一种合适的最低工资制度在我国可能会产生以下三种效应:第一,最低工资制度具有改善我国收入分配格局,缩小收入差距的功能;第二,一个各地区有差别的最低工资限制可能会促进我国的产业结构向内地转移,促进我国的产业结构升级;第三,长期来看,最低工资限制可能会强制低人力资本工资进行人力资本投资,有助于我国人力资本的提升.     

Generalized discrete discrepancy and its applications in experimental designs

In recent years, there has been increasing interest in the study of discrete discrepancy. In this paper, the popular discrete discrepancy is extended to the so-called generalized discrete discrepancy. Connections among generalized discrete discrepancy and other optimality criteria, such as orthogonality, generalized minimum aberration and minimum moment aberration, are investigated. These connections provide strong statistical justification of generalized discrete discrepancy. A lower bound of generalized discrete discrepancy is also obtained, which serves as an important benchmark of design uniformity.