When outcome heterogeneously matters for selection: a generalized selection correction estimator

The classical Heckman (1976, 1979) selection correction estimator (heckit) is misspecified and inconsistent, if an interaction of the outcome variable with an explanatory variable matters for selection. To address this specification problem, a full information maximum likelihood (FIML) estimator and a simple two-step estimator are developed. Monte Carlo (MC) simulations illustrate that the bias of the ordinary heckit estimator is removed by these generalized estimation procedures. Along with OLS and ordinary heckit, we apply these estimators to data from a randomized trial that evaluates the effectiveness of financial incentives for reducing obesity. Estimation results indicate that the choice of the estimation procedure clearly matters.     

Bayesian forecasting of federal funds target rate decisions

In this paper we examine which macroeconomic and financial variables have most predictive ability for the federal funds target rate decisions made by the Federal Open Market Committee (FOMC). We conduct the analysis for the 157 FOMC decisions during the period January 1990–June 2008, using dynamic ordered probit models with a Bayesian endogenous variable selection methodology and real-time data for a set of 33 candidate predictor variables. We find that indicators of economic activity and forward-looking term structure variables, as well as survey measures are most informative from a forecasting perspective. For the full sample period, in-sample probability forecasts achieve a hit rate of 90%. Based on out-of-sample forecasts for the period January 2001–June 2008, 82% of the FOMC decisions are predicted correctly.     

变频器共用直流母线技术在H型钢生产线上的应用

本文主要介绍了首钢长治钢铁有限公司H型钢厂采用变频器共用直流母线技术在H型钢生产线上的应用情况。     

Becoming fully functional: The conceptual struggle for a new structure for the giant corporation in the US and UK in the first half of the twentieth century

The rapid growth of the larger corporations in the US from the late nineteenth century onwards made the question of the appropriate structure for these new corporate giants of increasing importance to management writers. Particularly difficult was the relationship between line management and functional management as management hierarchies lengthened and specialisms grew in number and scope. Developing ideas from F.W. Taylor and Harrington Emerson by US and UK writers brought confusion as much as it brought progress. Attempts from the late 1920s to evolve organisational proposals by establishing principles of organisation brought modest advances but no conceptual breakthroughs. By the Second World War no management writers appear to have proposed or identified anything resembling the multidivisional form.     

我国发展铁路快捷货运战略思考

在快捷货运需求快速增长的背景下,发展铁路快捷货运不仅是满足经济社会发展和适应经济发展方式转变的需要,也是构建现代物流体系和提高铁路经济效益的需要.尽管近年来铁路快捷货运取得较快发展,但总体滞后于公路、民航.在对铁路快捷货运发展进行态势分析,详解其外部环境、内部条件、铁路优劣势以及面临机遇和挑战的基础上,提出我国发展铁路快捷货运的战略选择和战略重点.分析阐明铁路只要积极实施“扭转型战略”,抓住机遇,突出重点,加快发展,完全有条件扭转在快捷货运市场竞争中的被动局面.     

What is required for greener supplier selection? A literature review and conceptual model development

This paper examines the existing literature on green supplier selection. In total, 60 articles are reviewed, all published in peer-reviewed journals between 1991 and 2011. The articles are analyzed in terms of several general variables such as type of research and theoretical viewpoint, as well as more specific variables such as the supply chain position considered, stages of the supplier selection process studied, and the perspective taken on environmental criteria. The main findings are threefold. First, analytical research, focusing on developing normative decision models for the final stage in green supplier selection is clearly most dominant, employing a wide range of techniques. Second, empirical research is less prominent and generally lacks a clear theoretical background. Third, very little conceptual research has been done linking green supplier selection to an organization's strategy. Research on green supplier selection is highly fragmented and in danger of overemphasizing the technical aspects of supplier selection. Based on this review of the articles, a conceptual model of green supplier selection is presented, aimed at integrating the different dimensions of green supplier selection and identifying directions for future research.     

变压器在线故障监测可行性分析

本文根据现场实际工作经验,针对干式变压器的缺陷设计,提出了干式变压器的在线故障监测解决方案的可行性分析,为干式变压器在实际生产中故障排除提供帮助,为干式变压器设计和安全运行提供新的思路。     

危机事件对张家界旅游影响评价——基于本底线模型的高分辨率分析

根据张家界2001—2011年旅游统计数据,建立入境旅游客流量及旅游外汇收入、国内旅游客流量及旅游收入四条本底趋势线,引入月指数的概念,基于本底线模型的高分辨率分析危机事件对张家界旅游的影响。研究表明,旅游业既是一个敏感性产业,又是一个自我恢复力强的产业,在危机之后往往能强力反弹,旅游本底趋势线作为旅游业发展的生命线,始终能够把危机形成的凹型谷吸引回来。研究认为,张家界作为国内外知名品牌景区,具有抗周期性和后危机反弹的特征,尤其是国内旅游具有更强的抗周期性和后危机反弹能力,而入境旅游相对更脆弱。此外,作为国际性危机事件,"SARS"和"国际金融危机"对张家界旅游影响较大,周期较长;而"自然灾害"对张家界旅游影响相对较小。研究成果为张家界建立危机预警系统和管理体制提供了科学依据。     

运用电子游戏培养儿童自然观察智能的选择策略研究

本文拟从电子游戏系统结构入手,以多元智能理论为指导,分析电子游戏中的自然观察智能因素,并对电子游戏中的自然观察智能进行分类,探讨培养自然观察智能的电子游戏选择模型,并通过实验得以验证。为采用电子游戏提高自然观察智能的相关研究提供参考。     

Refinements and incentive efficiency in Walrasian models of insurance economies

The literature on Walrasian markets in large economies with adverse selection has used various equilibrium refinements, but has obtained no general incentive efficiency of equilibrium, namely when cross-subsidies are needed for efficiency. We show that the same refined equilibria may also be incentive inefficient even when general mechanisms that allow for such cross-subsidies are priced and can be traded. In the process, we also prove existence of some type of forward induction equilibria in this context.