Consistent inference in fixed-effects stochastic frontier models

The classical stochastic frontier panel data models provide no mechanism to disentangle individual time invariant unobserved heterogeneity from inefficiency. Greene (2005a, b) proposed the so-called “true” fixed-effects specification that distinguishes these two latent components. However, due to the incidental parameters problem, his maximum likelihood estimator may lead to biased variance estimates. We propose two alternative estimators that achieve consistency for $n\to \infty$ with fixed $T$. Furthermore, we extend the Chen et al. (2014) results providing a feasible estimator when the inefficiency is heteroskedastic and follows a first-order autoregressive process. We investigate the behavior of the proposed estimators through Monte Carlo simulations showing good finite sample properties, especially in small samples. An application to hospitals’ technical efficiency illustrates the usefulness of the new approach.     

Convenient estimators for the panel probit model: Further results

Bertschek and Lechner (1998) propose several variants of a GMM estimator based on the period specific regression functions for the panel probit model. The analysis is motivated by the complexity of maximum likelihood estimation and the possibly excessive amount of time involved in maximum simulated likelihood estimation. But, for applications of the size considered in their study, full likelihood estimation is actually straightforward, and resort to GMM estimation for convenience is unnecessary. In this note, we reconsider maximum likelihood based estimation of their panel probit model then examine some extensions which can exploit the heterogeneity contained in their panel data set. Empirical results are obtained using the data set employed in the earlier study. Helpful comments and suggestions by Irene Bertschek and Michael Lechner are gratefully acknowledged. This paper has also benefited from comments by two anonymous referees and from seminar participants at the Center for Health Economics at the University of York. Any remaining errors are the responsibility of the author.     

The British low-wage sector and the employment prospects of the unemployed

Are low wages a way for the unemployed to switch to higher-paying jobs? Using data from the British Household Panel Survey, the labour market dynamics of unemployed, low-paid and higher-paid employed men are analysed. Moreover, the respective (un)employment duration and occupational skill level are accounted for. Results show that in general low wages significantly reduce the risk of future unemployment and increase the chances of ascending the salary ladder, especially in the case of long-term unemployment (>360 days). Furthermore, the occupational skill level has a substantial influence on the upward mobility of low-paid jobs: individuals working in the initial period in a low-paid and higher-skilled occupation have on average an 11 percentage points higher probability of entering higher pay compared to when working in a low-paid and low-skilled occupation.     

遗传模拟退火算法在配送中心选址中的应用

物流配送中心是现代物流系统的枢纽,而配送中心地址的确定是物流系统分析的核心内容.合理的配送中心选址可以降低企业的运营成本,本文根据配送中心地址问题的特点和要求,提出用遗传模拟退火算法解决选址模型.最后通过一个实例求得了模型的最优解,验证了该算法的有效性.     

基于混合优化算法的带时间窗的车辆调度问题求解研究

论文建立了带时间窗的车辆调度问题的数学模型，并针对遗传算法在局部搜索能力方面的不足，提出将模拟退火算法与遗传算法相结合，从而构造了求解车辆调度问题的混合优化算法，并进行了实验计算。计算结果表明，用这种混合优化算法求解车辆调度问题，可以在一定程度上用模拟退火算法突跳性克服遗传算法在局部搜索能力方面的不足，从而得到质量较高的解。     

中国期权市场运作规则的制定与验证研究

笔者以郑商所期权核心规则制定和期权模拟测试结果为例进行分析。介绍中国期权市场运作研究项目背景,研究期权市场的重要功能、期权市场与期货市场关系,探讨中国期权上市的可行性以及如何进一步做好期权上市准备工作、加快上市步伐等实际运作问题。     

基于模拟退火算法的智能天线广播波束权值生成方法

文章采用模拟退火与随机搜索相结合的优化算法,给出了智能天线广播波束赋形中特定形状广播波束所对应的权值生成方法。依据智能天线系统扇区覆盖模式的要求,并结合智能天线的阵列结构,利用模拟退火与随机搜索相结合的优化算法可得到每个阵元所需设置的幅度和相位权值。该方法适用于特殊广播波束的情况,对智能天线技术的应用具有重要意义。     

Institutional Market Power in Comté: Insights from a ‘Double Marginalisation’ Model

This article explores the economic efficiency of a horizontally and vertically coordinated industry where upstream producers are atomised, but downstream processors are few, explicitly considering participation incentives and allowing the coordinated industry to exert market power towards buyers. The model offers insight into the probable social impacts of the government‐sanctioned supply control scheme in place in the French Comté cheese market, suggesting it falls short of constituting a Pareto‐improvement compared with a laissez‐faire situation. More generally, our theoretical model provides guidance to identify instances where encouraging industry coordination may be socially desirable. We formally introduce the concept of ‘seller‐equivalent degree of overall market power’ of the separated industry, a market characteristic comprised of measurable or inferable parameters, the value of which is shown to determine the potential for Pareto improvements through industry integration.     

高职楼宇智能化专业毕业综合实践环节的教学改革尝试

楼宇自动化（BA）系统课程实训的核心任务是以实验室里的中央空调模拟系统为对象进行BA监控系统的设计，并撰写设计报告。原有实训的内容设计比较枯燥乏味，与毕业后所从事的实际工作环境脱节，学生缺乏竞争压力，创造力难以发挥体现。因此，引入工程招投标机制，模拟竟标环境，让学生充分调动所学知识，亲历竞争场景，从而得到锻炼和提高，这是楼宇智能化专业毕业综合实践改革的有益尝试。     

Broadening the concept of rational economic behavior: A case study of cheese making at the Abbey of Tamié

Through an analysis of the business activities of a Trappist monastery, an attempt is made to add to the understanding of how ethical considerations, custom, and culture, as well as the profit motive, affect how actual economic decisions are made. This analysis is implemented through a case study of the cheese-making business of a monastery in the French Alps where the tradition of cheese, agriculture, and monks is important to the culture and customs of the area. The analysis finds that the monks are able to successfully conduct their business in ways that honor their custom and culture within the religious confines imposed by the monastery.