Selecting the Correct Number of Factors in Approximate Factor Models: The Large Panel Case With Group Bridge Estimators

This article proposes a group bridge estimator to select the correct number of factors in approximate factor models. It contributes to the literature on shrinkage estimation and factor models by extending the conventional bridge estimator from a single equation to a large panel context. The proposed estimator can consistently estimate the factor loadings of relevant factors and shrink the loadings of irrelevant factors to zero with a probability approaching one. Hence, it provides a consistent estimate for the number of factors. We also propose an algorithm for the new estimator; Monte Carlo experiments show that our algorithm converges reasonably fast and that our estimator has very good performance in small samples. An empirical example is also presented based on a commonly used U.S. macroeconomic dataset.     

论詹姆逊后现代马克思主义理论的三个直接来源

詹姆逊的独特贡献表现为:对第二次世界大战之后的资本主义文化特质做出了总体性揭示,提出了后现代主义是晚期资本主义的文化逻辑的重要论断。其理论具有深刻的马克思主义底蕴,主要表现为三个直接的理论来源:比利时著名的马克思主义经济学家曼德尔的晚期资本主义理论;英国著名的马克思主义理论家威廉斯关于主导文化、残余文化和新兴文化的文化系统理论;马克思主义的生产方式理论。在三个直接的理论来源中,马克思主义理论重要价值和詹姆逊自身的理论立场被充分彰显,进一步确证了他的继西方马克思主义之后的当之无愧的后现代马克思主义领军人物的身份。     

组织结构对组织学习与知识转化关系影响研究

创新依赖于组织学习。但是,知识如果没有在组织中被充分的分享,那么它的作用是有限的。即,为了实现知识的转化,知识分享的支持系统——有效的组织结构必须存在。本文通过组织学习的角度,探讨组织学习与知识转化的关系,以及组织结构的障碍在其中如何发挥作用。     

中国居民消费价格指数间的关系与选择

居民消费价格是宏观经济监测的重要内容之一,其指数间的关系与选择具有重要意义。通过与国外发达国家的比较,从我国目前价格指数编制和选择使用的现状及存在的问题出发,研究环比、同比和定基价格指数以及环比“折年率”之间的相互转化情况和它们各自在经济监测中的特征。重点研究了基于X-12-ARIMA模型的环比价格指数的季节调整和同比价格指数相对环比价格指数对物价监测的时滞性。同时验证了研究中同比向定基指数转化的合理性。由此对我国居民价格实时监测的指数选择提供政策建议,也为我国价格指数的编制提出建议。     

论个群目标一致性机理及和谐管理路径

在日趋成熟的市场经济中,品牌已由简单意义上的产品标识演化为综合企业形象,产品质量和文化内涵的鲜明标志,成为企业进行市场营销的主力.在激烈的品牌竞争中,品牌中的文化内蕴成为其标志和灵魂,发挥着重要的市场营销的作用,左右着品牌在市场中的地位.这种无形的"文化力"影响可遍及现代社会经济运营的各个方面,深刻的改变着消费者的意识和行为,为企业打造强势品牌,增强品牌竞争力提供有利的支撑.本文通过对企业品牌竞争与品牌文化的关系探讨,品牌内涵演变以及消费者行为变化对品牌文化需求的必然性分析,着重论述了企业品牌竞争中的文化力作用.     

Deconstructing the silences: gay social memory

Adopting a Foucaultian perceptive, this article deconstructs the silences in the Singaporean gay community. The collective absences in homosexuals' social memory is not simply reflective of a fragmented community, but must be comprehended in relation to the role of the state and media in shaping particular discourses.     

Point and interval forecasts of age-specific fertility rates: a comparison of functional principal component methods

Accurate forecasts of age-specific fertility rates are critical for government policy, planning and decision making. With the availability of the Human Fertility Database (2011), the paper compares the empirical accuracy of the point and interval forecasts, obtained by the approach of Hyndman and Ullah (Comput Stat Data Anal 51(10), 4942?C4956, 2007) and its variants for forecasting age-specific fertility rates. The analyses are carried out using the age-specific fertility data of 15 mostly developed countries. Based on the one-step-ahead to 20-step-ahead forecast error measures, the weighted Hyndman-Ullah method provides the most accurate point and interval forecasts for forecasting age-specific fertility rates, among all the methods we investigated.     

Some Theoretical Comparisons of Negative Binomial and Zero-Inflated Poisson Distributions

In this article, we compare the zero-inflated Poisson (ZIP) and negative binomial (NB) distributions based on three most important criteria: the probability of zero, the mean value, and the variance. Our results show that with same mean value and variance, the ZIP distribution always has a larger probability of zeros; with same mean value and probability of zeros, the NB distribution always has a larger variance; and with same variance and probability of zeros, the ZIP distribution always has a larger mean value. We also study the properties of Vuong test in model selection in three cases by simulations.     

Starting Values for EM Estimation of Latent Class Joint Model

Latent class model is one of the important latent variable methods for joint modeling longitudinal and survival data. Latent class joint model can handle underlying heterogeneous population, discover subpopulation structure, and incorporate correlated non normally distributed outcomes. The maximum likelihood estimates of parameters in latent class joint model are generally obtained by the EM algorithm. Finding the starting values is one of the major issues to implement the EM algorithm successfully. In this article, initial value formulas are provided, a simulation study is conducted to show that the proposed starting values perform very well, and two illustrative examples are presented.     

Hybrid Bayesian inference on HIV viral dynamic models

Modelling of HIV dynamics in AIDS research has greatly improved our understanding of the pathogenesis of HIV-1 infection and guided for the treatment of AIDS patients and evaluation of antiretroviral therapies. Some of the model parameters may have practical meanings with prior knowledge available, but others might not have prior knowledge. Incorporating priors can improve the statistical inference. Although there have been extensive Bayesian and frequentist estimation methods for the viral dynamic models, little work has been done on making simultaneous inference about the Bayesian and frequentist parameters. In this article, we propose a hybrid Bayesian inference approach for viral dynamic nonlinear mixed-effects models using the Bayesian frequentist hybrid theory developed in Yuan [Bayesian frequentist hybrid inference, Ann. Statist. 37 (2009), pp. 2458–2501]. Compared with frequentist inference in a real example and two simulation examples, the hybrid Bayesian approach is able to improve the inference accuracy without compromising the computational load.