Stochastic frontier models with multiple time-varying individual effects

This paper proposes a flexible time-varying stochastic frontier model. Similarly to Lee and Schmidt [1993, In: Fried H, Lovell CAK, Schmidt S (eds) The measurement of productive efficiency: techniques and applications. Oxford University Press, Oxford], we assume that individual firms’ technical inefficiencies vary over time. However, the model, which we call the “multiple time-varying individual effects” model, is more general in that it allows multiple factors determining firm-specific time-varying technical inefficiencies. This allows the temporal pattern of inefficiency to vary over firms. The number of such factors can be consistently estimated. The model is applied to data on Indonesian rice farms, and the changes in the efficiency rankings of farms over time demonstrate the model’s flexibility.

The impact of high value markets on smallholder productivity in the Ecuadorean Sierra: A Stochastic Production Frontier approach correcting for selectivity bias

This paper uses data from small-scale potato farmers in Ecuador to examine the impact of the program Plataformas de Concertación on productivity growth. Using propensity score matching combined with a Stochastic Production Frontier model that corrects for sample selection bias, we disaggregate the yield growth attributable to the program into technological change (TC) and technical efficiency (TE). While the results do not exhibit a clear indication of selection bias, the analysis does show that on average beneficiaries exhibit higher yields than control farmers given the same input levels, but lower TE with respect to their own frontiers. These results suggest that while the program raised the technology gap in favor of beneficiaries, it had a negative effect on TE in the short run. The latter finding is consistent with the notion that beneficiaries enjoyed a significant change in production techniques, but it is very likely that they were still in the “learning by doing” stages at the time the data was collected. In fact, the results suggest a fast recovery in TE levels on the part of beneficiaries as time with project increased.     

Rural hospital performance and its correlates

The cost, technical, allocative and scale efficiencies of a sample of rural U.S. hospitals are calculated via linear programming models. Tobit analysis is used to assess possible correlates of each of the efficiency measures. A large amount of dispersion in operating efficiency is found within our data set; the majority of the dispersion is due to technical inefficiency. In general, for-profit hospitals are found to outperform not-for-profit and public hospitals. Demand characteristics, quality of care, and the mix of services offered are also found to influence performance.     

Supply Restricted Telecommunications Markets: The Effect of Technical Efficiency on Waiting Times

The paper is concerned with supply constraints in the provision of telecommunications services. As a measure of supply constraint we use the average waiting time for telephone connections. Duration models are employed to analyze a panel data set for 28 countries. In addition to economic variables, we consider the role of technical efficiency in causing supply constraints. Stochastic frontiers are used to determine the technical efficiency with which countries use labor and capital inputs to connect customers. When technical efficiency is included in duration models for waiting times until connection, we find that it is the major determinant.     

Specification of Distance Functions Using Semi- and Nonparametric Methods with an Application to the Dynamic Performance of Eastern and Western European Air Carriers

In this paper we examine the productive performance of a group of three East European carriers and compare it to thirteen of their West European competitors during the period 1977–1990. We first model the multiple output/multiple input technology with a stochastic distance frontier using recently developed semiparametric efficient methods. The endogeneity of multiple outputs is addressed in part by introducing multivariate kernel estimators for the joint distribution of the multiple outputs and potentially correlated firm random effects. We augment estimates from our semiparametric stochastic distance function with nonparametric distance function methods, using linear programming techniques, as well as with extended decomposition methods, based on the Malmquist index number. Both semi- and nonparametric methods indicate significant slack in resource utilization in the East European carriers relative to their Western counterparts, and limited convergence in efficiency or technical change between them. The implications are rather stark for the long run viability of the East European carriers in our sample.     

国外投资者关系管理价值效应研究前沿述评

投资者关系管理是一种有价值的管理活动,国外丰富的研究成果值得借鉴和学习.IRM的价值路径主要有两条:一是直接价值效应.主要体现IRM在改善和提高企业声誉、增加公司可见度、吸引机构投资者等方面具有直接的贡献；二是间接价值效应.主要体现在长期有效的IRM能够发挥降低资本成本、提高股价以及最终提升公司价值等作用.通过梳理国外有关IRM价值相关性研究成果,把握IRM研究前沿,为我国相关理论研究和企业实践提供经验借鉴.     

国内管制经济学的发展、理论前沿与热点问题

管制经济学是一门新兴学科,正确认识国内管制经济学的发展现状,准确把握国内管制经济学的理论前沿和热点问题,将有助于国内管制经济学的理论创新与实际应用.本文在对国内管制经济学的发展脉络进行梳理的基础上,对国内管制经济学的理论前沿和热点问题进行分析,试图推动中国管制经济学的进一步发展.     

Proxy variable estimation of productivity and efficiency

We model productivity and inefficiency jointly, instead of modeling and estimating either only productivity or only inefficiency with many variable and quasi-fixed inputs. In the first model, we use a multi-step procedure. We use the proxy variable method based on the first-order condition (FOC) of expected profit maximization with respect to the single variable input to take care of the endogeneity problem arising from both productivity and inefficiency. To separate mean inefficiency from mean productivity we assume them nonparametric functions of different sets of exogenous variables. In the second model, we consider a novel system consisting of the production function and the FOCs of expected profit maximization for the multiple variable inputs. Distributional assumptions are made on all the random errors associated with the production function, the FOCs, productivity, and inefficiency functions in the second model. We use the Colombian food manufacturing data as an application of our model.     

物流科技领域研究热点和研究前沿分析

利用海量科技文献数据挖掘和识别全球先进物流科技的研究热点和研究前沿，把握物流科技领域发展趋势，对中国引领全球物流科技发展、确保供应链安全具有重要参考价值。结合文献计量法、知识图谱、突变探测算法，以Web of Science（WOS)核心合集论文数据为对象，利用CiteSpace关键词共现网络、主题聚类、突变检测等方法进行计算和可视化分析。研究识别发现物流科技领域研究热点主要集中在物流供应链各环节优化技术，包括信息科技、系统平台等硬件创新科技成果应用，以及模型算法、网络设计等软件性能改进；研究前沿包括“信息”“工业4.0”“大数据”“模型”“协同”等。     

Natural and cyclical unemployment: A stochastic frontier decomposition and economic policy implications

This work splits effective unemployment into two components: natural unemployment, and cyclical unemployment. For that purpose, an estimation of the stochastic cost frontier is performed. The study is focused on the 17 autonomous communities in Spain over the period 1982–2012. Results evidence greater importance of the natural component as the principal determinant of effective unemployment. When comparing these results with those obtained applying univariate filters, the distribution in the components of the effective unemployment changes, increasing the importance of cyclical unemployment. This result indicates that the policymakers should have a greater power to implement aggregate demand policies.