Energy performance evaluation of OECD countries using Bayesian stochastic frontier analysis and Bayesian network classifiers

More recently a large amount of interest has been devoted to the use of Bayesian methods for deriving parameter estimates of the stochastic frontier analysis. Bayesian stochastic frontier analysis (BSFA) seems to be a useful method to assess the efficiency in energy sector. However, BSFA results do not expose the multiple relationships between input and output variables and energy efficiency. This study proposes a framework to make inferences about BSFA efficiencies, recognizing the underlying relationships between variables and efficiency, using Bayesian network (BN) approach. BN classifiers are proposed as a method to analyze the results obtained from BSFA.     

基于潜类别随机前沿的区域创新效率及其影响因素分析

运用可根据研究对象的潜在属性内生分组的潜类别随机前沿模型,采用1999-2012年中国各省区数据,研究各省区的创新效率及影响因素。结果表明:以人力资本水平和基础设施状况为条件变量,将全国各省区分成两个技术类别,分别有各自的技术前沿和函数形式,A类别中上海市的创新效率最高,B类别中河北省的创新效率最高;平均来看,各类的创新效率均呈上升趋势,贸易开放、产业结构和金融发展对创新效率均有显著的正向作用,同时创新效率在各类内部均存在俱乐部收敛。     

Distribution of cost inefficiency in stochastic frontier approach: evidence from Spanish banking

The aim of the paper is to demonstrate the appropriateness of an a priori analysis to determine the distributional assumption of the inefficiency term in a stochastic frontier model. To this end, theoretical distributions of estimated inefficiency were obtained when the inefficiency term is assumed to be distributed as a half normal and an exponential in a cost frontier model. Comparisons of such theoretical distributions with the respective cost inefficiency estimators using the goodness of fit test allow selecting the most appropriate distributional assumption. The application on three data sets of Spanish banking system in 2009 demonstrated the relevance of the research question. First, the results of estimated cost inefficiency with a half normal assumption are larger than with an exponential distribution significantly. Besides, half normal assumption was rejected and exponential was not rejected as the most appropriate distribution of inefficiency term in Spanish banking data set. However, the adjustment of saving banks data had been better with the former distribution than the latter. In the case of banks, any distribution results appropriate. To sum up, this work demonstrate that the distributional assumption on inefficiency term in Stochastic Frontier Approach must be established in a justified way, as it can significantly bias the results of estimated inefficiency and therefore, influences improving policies and strategies in the Spanish banking sector.     

Efficiency Measure from Dynamic Stochastic Production Frontier: Application to Tunisian Textile, Clothing, and Leather Industries

This paper adresses the measurement of technical efficiency of textile, clothing, and leather (TCL) industries in Tunisia through a panel data estimation of a dynamic translog production frontier. It provides a perspective on productivity and efficiency that should be instructive to a developing economy which will face substantial competitive pressure along the gradual economic liberalisation process. The importance of TCL industries in Tunisian manufacturing sector is a reason for obtaining more knowledge of productivity and efficiency for this key industry. Dynamic is introduced to reflect the production consequences of the adjustment costs, which are associated with changes in factor inputs. Estimation of a dynamic error components model is considered using the system generalized method of moments (GMM) estimator suggested by Arellano and Bover (1995), Another look at the instrumental-variable estimation of error-components models, J. Econometrics68:29-51) and Blundell and Bond (Blundell, R., Bond, S. (1998a), Initial conditions and moment restrictions in dynamic panel data models. J. Econometrics87:115-143; Blundell, R., Bond, S. (1998b), GMM estimation with persistent panel data: an application to production functions, Paper presented at the Eighth International Conference on Panel Data, Goteborg University). Our study evaluates the sensitivity of the results, particularly of the efficiency measures, to different specifications. Firm-specific time-invariant technical efficiency is obtained using the Schmidt and Sickles (Schmidt, P., Sickles, R. C. (1984). Production frontiers and panel data. J. Bus. Econ. Stat.2:367-374) approach after estimating the dynamic frontier. We stress the importance of allowing for lags in adjustment of output to inputs and of controlling for time-invariant variables when estimating firm-specific efficiency. The results suggest that the system GMM estimation of the dynamic specification produces the most accurate parameter estimates and technical efficiency measure. Mean efficiency scores is of 68%. Policy implications of the results are outlined.     

考虑环境变量的网络DEA模型

本文放松环境同质性的假定条件,构建包含环境变量的网络DEA模型,测度环境变量对生产前沿及生产决策单元效率的影响效应。构建的模型放松了投入产出变量集合与环境变量集合间的独立性假定,并且不需要先验性的判断环境变量的作用方向,弥补了现有处理环境变量方法的不足。提出的距离函数是一种非径向非导向的效率测度类型,能够有效地测度所有潜在松弛。Monte Carlo模拟结果表明本文构建的模型能够很好的测度环境变量对整体生产过程及其子生产过程的作用效应,创新生产过程分析结果表明出口依存度与技术创新效率间存在负相关关系,不考虑环境变量作用效应下测度的省际技术创新效率排名存在较大偏误。     

基于等级差异的公立医院效率及其影响因素分析

使用2010年江苏省261家公立医院的数据,对不同等级的公立医院效率及其影响因素进行比较与分析.基于随机前沿方法,利用柯布—道格拉斯生产函数和成本函数分别计算了江苏省不同等级不同类别公立医院的技术效率与成本效率.在此基础上,使用Tobit回归方法分析影响医院效率的因素,回归结果显示,不同级别公立医院效率影响因素差异较大,一级和三级公立医院可以通过降低人均门诊费用、增加人均住院费用的方式提高效率,而二级公立医院主要通过增加职业医师比例来提高效率.     

The Implications of Using Messy Data to Estimate Production-Frontier-Based Technical Efficiency Measures

An empirical study of efficiency at the plant level, requiring production and financial data, was done using frontier function specifications. It is not evident from the implementation of the production-frontier models that different methodologies will consistently flag the same observations as being efficient or inefficient. As a result, outlier diagnostics for individual observations and for subsets of observations are used to achieve a relative index of influentiality within the spectrum of efficiency. These outlier diagnostic tests consistently flag the same subset of efficient and inefficient observations as the frontier models and additionally clarify ranking discrepancies among the frontier model specifications.     

Estimating technical efficiency with non-neutral shift of the frontier

In the literature, technical efficiency is measured as the ratio of the observed output to potential output. Although there is no a priori theoretical reasoning, in the stochastic framework of measuring technical efficiency, potential output has been conventionally assumed as a neutral shift from observed output, owing solely to a larger intercept term in the frontier production function and without change in the input response coefficients. The objective of this paper is to propose and apply a method to measure technical efficiency without the above assumption. Furthermore, this methodology does not require the restrictive assumption of a particular distribution for the efficiency-related error term, as has been the case until now in the stochastic production function literature. A random sample of farmers from Madurai district in Tamil Nadu, India, was used. The analysis revealed substantial variation in the farm-specific input response coefficients between farms, which means that the contributions of individual inputs to the output differ from farm to farm, because the methods of application of the individual inputs vary. The frontier production function, which defines the potential of a technology, is determined by the highest values of the coefficients of each individual input which may come from one or more farms. Farm-specific frontier functions generally showed a considerable potential for improving the technical.performance of each input.     

Test for randomness of the technology parameter in a stochastic frontier regression model

This paper considers the problem of testing for randomness of the technology parameter in a stochastic frontier regression model. A test statistic is proposed and its asymptotic distribution theory is discussed. Simulation results show that the proposed test maintains its level and also quite powerful against various alternatives. An empirical investigation has been carried out by applying the suggested test procedure to the data set on electric utility companies. The results are consistent with the general finding that the technology parameter of the stochastic frontier model used for modeling these data is random.     

A general methodology for bootstrapping in non-parametric frontier models

The Data Envelopment Analysis method has been extensively used in the literature to provide measures of firms' technical efficiency. These measures allow rankings of firms by their apparent performance. The underlying frontier model is non-parametric since no particular functional form is assumed for the frontier model. Since the observations result from some data-generating process, the statistical properties of the estimated efficiency measures are essential for their interpretations. In the general multi-output multi-input framework, the bootstrap seems to offer the only means of inferring these properties (i.e. to estimate the bias and variance, and to construct confidence intervals). This paper proposes a general methodology for bootstrapping in frontier models, extending the more restrictive method proposed in Simar & Wilson (1998) by allowing for heterogeneity in the structure of efficiency. A numerical illustration with real data is provided to illustrate the methodology.     

Work effort, technical efficiency and productivity growth

This paper develops a model to examine labor-use efficiency associated with the effieciency wage theory and technical effieciency associated with the frontier production model. The generalixed modelcombines these two approaches and derives measures of technical and labor-use efficiency as well as their effects on productivity growth. It also seperates technical inefficiency from industry heterogenity. the model is applied to estimate loss of output due to technical and labor-use inefficiency for 18 two-digit U.S manufacturing industries using time series and cross-sectional data.     

Work effort,technical efficiency and productivity growth

This paper develops a model to examine labor-use efficiency associated with the effieciency wage theory and technical effieciency associated with the frontier production model. The generalixed modelcombines these two approaches and derives measures of technical and labor-use efficiency as well as their effects on productivity growth. It also seperates technical inefficiency from industry heterogenity. the model is applied to estimate loss of output due to technical and labor-use inefficiency for 18 two-digit U.S manufacturing industries using time series and cross-sectional data.     

Flexible reliability assessment of digital circuits based on signal probability

In order to evaluate the reliability of VLSI, a level matrix for reliability and signal propagation evaluation is proposed based on the combination of probabilistic transfer matrix and signal probability reliability. By appropriate operations of the proposed matrix, reliability and signal probability of the entire circuit as well as the individual output(s) can be obtained flexibly. This new approach realizes hierarchical calculation by the proposed level matrix propagated from the previous state instead of the primary one. The efficiency and feasibility of the proposed method have been verified by both combinational and sequential benchmark circuits.     

中国国民经济核算的新发展和SNA修订的挑战

2004年经济普查之后,中国国内生产总值核算发生了若干方面变化,包括经济普查年度国内生产总值核算在资料来源、计算方法、生产范围、基本分类和某些具体问题处理方法等方面的修订,国内生产总值历史数据的修订,以及非经济普查年度国内生产总值核算方案的制定;在机构部门账户发生的若干方面变化,包括机构部门账户部门分类的细化和编制方法的修订;而1993年SNA的修订中国国民经济核算所面临的挑战,包括中央银行产出、非正规部门、政府与公共企业的交易--股权投资收益和资本注入等方面的修订对中国国民经济核算的挑战.     

Conditional time-dependent nonparametric estimators with an application to healthcare production function

ABSTRACT

By using the probabilistic framework of production efficiency, the paper develops time-dependent conditional efficiency estimators performing a non-parametric frontier analysis. Specifically, by applying both full and quantile (robust) time-dependent conditional estimators, it models the dynamic effect of health expenditure on countries’ technological change and technological catch-up levels. The results from the application reveal that the effect of per capita health expenditure on countries’ technological change and technological catch-up is nonlinear and is subject to countries’ specific income levels.     

Frontier estimation using kernel smoothing estimators with data transformation

In economics, a production frontier function is a graph that shows the maximum output of production units such as firms, industries, or economies, as a function of their inputs. Practically, estimating production frontiers often requires imposition of constraints such as monotonicity or monotone concavity. However, few constrained estimators of production frontier have been proposed in the literature. They are based on simple envelopment techniques which often suffer from lack of precision and smoothness. Motivated by this observation, we propose a smooth constrained nonparametric frontier estimator respecting constraints by considering kernel smoothing estimators from a transformed data. It is particularly appealing to practitioners who would like to use smooth estimates that, in addition, satisfy theoretical axioms of production. The utility of this method is illustrated through application to one real dataset and simulation evidences are also presented to show its superiority over the most known methods.     

Measuring the efficiency of public services: the limits of analysis

Summary.  Policy makers are increasingly seeking to develop overall measures of the effi-ciency of public service organizations. For that, the use of 'off-the-shelf' statistical tools such as data envelopment analysis and stochastic frontier analysis have been advocated as tools to measure organizational efficiency. The analytical sophistication of such methods has reached an advanced stage of development. We discuss the context within which such models are deployed, their underlying assumptions and their usefulness for a regulator of public services. Four specific model building issues are discussed: the weights that are attached to public service outputs; the specification of the statistical model; the treatment of environmental influences on performance; the treatment of dynamic effects. The paper concludes with recommendations for policy makers and researchers on the development and use of efficiency measurement techniques.     

Semiparametric Estimation of Stochastic Production Frontier Models

This article extends the linear stochastic frontier model proposed by Aigner, Lovell, and Schmidt to a semiparametric frontier model in which the functional form of the production frontier is unspecified and the distributions of the composite error terms are of known form. Pseudolikelihood estimators of the parameters characterizing the two error terms of the model are constructed based on kernel estimation of the conditional mean function. The Monte Carlo results show that the proposed estimators perform well in finite samples. An empirical application is presented. Extensions to a partially linear frontier function and to more flexible one-sided error distributions than the half-normal are discussed     

动态面板空间随机前沿模型的参数估计及应用

生产效率一般会受到空间相关性和时间滞后效应的影响，不易准确测算。本文考虑时空双重滞后特征，提出一种动态面板数据空间随机前沿模型，针对模型的内生性问题，借鉴已有的估计方法，本文提出一种广义矩估计方法（Generalized Method of Moments，GMM），并证明了参数估计的一致性。在应用分析中，利用本文所提出的理论模型实证分析了我国战略性新兴产业发展的效率，该理论模型能够客观、科学地测算技术效率，实证结论验证了理论模型的应用效果。     

基于随机前沿分析的中国玉米生产技术效率研究

利用1995～2008年中国15个主要玉米产区的投入与产出面板数据建立了随机前沿生产函数模型,对中国玉米生产的技术效率进行了测算,全国玉米生产平均技术效率为0.824。在此基础上,进一步分析了技术效率的时间差异、地区差异及收敛性,发现玉米生产技术效率时间、地区差异明显,但从全国来看,各产区之间的玉米生产技术效率的差距正在逐步缩小,具有趋同趋势。提高玉米生产技术效率,需要在以下几个方面做出改进：加强对灾害的预防和监测工作,并有科学计划地兴修农田水利设施;加大种子用量,提高机械化水平,进行科学管理;加强玉米生产技术的研发和创新等。