东西部的贫富差距究竟有多大--西北民族地区同全国及东南沿海一些省市的比较分析

贫富差距是一个世界性的问题.本文从我国西北民族地区同全国及东南沿海一些省市的生产力发展水平、社会产业结构、固定资产投入、财政收支、人员素质、人口增长率及人民生活水平等一系列人均指标的对比分析中,更具体地认识到东西部差距在进一步拉大的客观事实.这种差距已经影响到社会的长治久安,经济的持续增长,各民族的团结,进而关系到坚持社会主义道路和方向的问题,从而引起了国家及社会普遍的关注.国家在加大对西部地区的投入,西部地区的各族人民更应该面对现实,艰苦奋斗,与时俱进,加快发展,以实现祖国各族人民共同繁荣、共同富裕的目的.     

论超文本叙事理念的源起

网络媒介的超文本叙事与技术层面的超文本、哲学及文学理论层面的超文本和小说家在创作中虚构的超文本三种超文本理念密切相关。技术层面的超文本满足日常生活的目的性,哲学意义的超文本则强调以新的文本形式彰显与传统思维的对抗,而小说家所虚构的超文本则是通过线性循环创作一种内容无限的读不完的书。在三种超文本理念的张力缝隙中,传统的线性叙事观念受到了挑战,新的超文本叙事不论从创作还是阅读都不像文学家和理论家所预想的那样盛景空前。     

大跨度独塔斜拉桥荷载试验与结构性能分析

介绍泰州某独塔斜拉桥成桥荷载试验的主要内容和方法,并结合有限元数值计算,对该桥梁结构的实测应力、挠度及振动特性进行对比分析。试验结果表明：该桥理论分析和设计计算方法可靠,桥梁刚度和承载能力满足设计要求。研究结果可为同类型桥梁的设计和成桥试验提供参考。     

中国共产党政治建设的百年回望及现实意义

重视党的政治建设,注重从政治上建党强党是党的优良传统和宝贵经验。马克思主义政党的根本要求和马克思主义政党学说的核心要义是党的政治建设深厚的理论渊源。回望党的政治建设百年历程,党的政治建设作为党的建设的有机组成部分,贯穿革命、建设和改革全过程,经历了开端发展、深入推进、创新发展的演进历程,取得了重大成就,积累了宝贵经验。新时代深入推进党的政治建设是保持党的先进性和纯洁性的必然选择、应对化解各类矛盾风险挑战的迫切需要、发挥党员干部先锋模范作用的内在要求。     

Which Factors are Risk Factors in Asset Pricing? A Model Scan Framework

Abstract

A key question for understanding the cross-section of expected returns of equities is the following: which factors, from a given collection of factors, are risk factors, equivalently, which factors are in the stochastic discount factor (SDF)? Though the SDF is unobserved, assumptions about which factors (from the available set of factors) are in the SDF restricts the joint distribution of factors in specific ways, as a consequence of the economic theory of asset pricing. A different starting collection of factors that go into the SDF leads to a different set of restrictions on the joint distribution of factors. The conditional distribution of equity returns has the same restricted form, regardless of what is assumed about the factors in the SDF, as long as the factors are traded, and hence the distribution of asset returns is irrelevant for isolating the risk-factors. The restricted factors models are distinct (nonnested) and do not arise by omitting or including a variable from a full model, thus precluding analysis by standard statistical variable selection methods, such as those based on the lasso and its variants. Instead, we develop what we call a Bayesian model scan strategy in which each factor is allowed to enter or not enter the SDF and the resulting restricted models (of which there are 114,674 in our empirical study) are simultaneously confronted with the data. We use a Student-t distribution for the factors, and model-specific independent Student-t distribution for the location parameters, a training sample to fix prior locations, and a creative way to arrive at the joint distribution of several other model-specific parameters from a single prior distribution. This allows our method to be essentially a scaleable and tuned-black-box method that can be applied across our large model space with little to no user-intervention. The model marginal likelihoods, and implied posterior model probabilities, are compared with the prior probability of 1/114,674 of each model to find the best-supported model, and thus the factors most likely to be in the SDF. We provide detailed simulation evidence about the high finite-sample accuracy of the method. Our empirical study with 13 leading factors reveals that the highest marginal likelihood model is a Student-t distributed factor model with 5 degrees of freedom and 8 risk factors.     

Social creativity as a function of agent cognition and network properties: A computer model

Inventions – concepts, devices, procedures – are often created by networks of interacting agents in which the agents can be individuals (as in a scientific discipline) or they can themselves be collectives (as in firms interacting in a market). Different collectives create and invent at different rates. It is plausible that the rate of invention is jointly determined by properties of the agents (e.g., their cognitive capacity) and by properties of the network of interactions (e.g., the density of the communication links), but little is known about such two-level interactions. We present an agent-based model of social creativity in which the individual agent captures key features of the human cognitive architecture derived from cognitive psychology, and the interactions are modeled by agents exchanging partial results of their symbolic processing of task information. We investigated the effect of agent and network properties on rates of invention and diffusion in the network via systematic parameter variations. Simulation runs show, among other results, that (a) the simulation exhibits network effects, i.e., the model captures the beneficial effect of collaboration; (b) the density of connections produces diminishing returns in term of the benefits on the invention rate; and (c) limits on the cognitive capacity of the individual agents have the counterintuitive consequence of focusing their efforts. Limitations and relations to other computer simulation models of creative collectives are discussed.     

A test for the variance residual life

In this paper we develop a test based on the empirical distribution function for the alternative representing 'decreasing variance residual life1 property. The test is consistent with asymptotically normal test statistic and is shown to perform well in the Pitman's asymptotic relative efficiency sense.     

Nonparametric repeated significance tests for some analysis of covariance models

For a general class of nonparametric analysis of covariance problems (with stochastic covariates), some repeated significance testing procedures are developed. These procedures rest on the construction of suitable rank order statistics based on the partial sequence of sample sizes and allow for a monitoring of experimentation with the objective of a possible early termination of experimentation. The basic theory is based on the weak convergence of certain stochastic processes relating to the rank order statistics. Various properties of the proposed tests are discussed.     

Estimation of the mean quality-adjusted survival using a multistate model for the sojourn times

In clinical trials, it may be of interest taking into account physical and emotional well-being in addition to survival when comparing treatments. Quality-adjusted survival time has the advantage of incorporating information about both survival time and quality-of-life. In this paper, we discuss the estimation of the expected value of the quality-adjusted survival, based on multistate models for the sojourn times in health states. Semiparametric and parametric (with exponential distribution) approaches are considered. A simulation study is presented to evaluate the performance of the proposed estimator and the jackknife resampling method is used to compute bias and variance of the estimator.     

考虑经营者合谋的激励机制研究

构建经营者不合谋和合谋2种情形下的委托-代理模型,对多个经营者的激励机制进行分析.基于此,提出了企业所有者为应对经营者合谋的机会主义行为应该采取的措施.