Multi-period efficiency and Malmquist productivity index in two-stage production systems

Conventional two-stage data envelopment analysis (DEA) models measure the overall performance of a production system composed of two stages (processes) in a specified period of time, where variations in different periods are ignored. This paper takes the operations of individual periods into account to develop a multi-period two-stage DEA model, which is able to measure the overall and period efficiencies at the same time, with the former expressed as a weighted average of the latter. Since the efficiency of a two-stage system in a period is the product of the two process efficiencies, the overall efficiency of a decision making unit (DMU) in the specified period of time can be decomposed into the process efficiency of each period. Based on this decomposition, the sources of inefficiency in a DMU can be identified. The efficiencies measured from the model can also be used to calculate a common-weight global Malmquist productivity index (MPI) between two periods, in that the overall MPI is the product of the two process MPIs. The non-life insurance industry in Taiwan is used to verify the proposed model, and to explain why some companies performed unsatisfactorily in the specified period of time.     

Sensitivity analysis of efficiency and Malmquist productivity indices: An application to Spanish savings banks

Hypothesis testing and statistical precision in the context of non-parametric efficiency and productivity measurement have been investigated since the early 1990s. Recent contributions focus on this matter through the use of resampling methods—i.e., bootstrapping techniques. However, empirical evidence is still practically non-existent. This gap is more noticeable in the case of banking efficiency studies, where the literature is immense. In this work, we explore productivity growth and productive efficiency for Spanish savings banks over the (initial) post-deregulation period 1992–1998 using Data Envelopment Analysis (DEA) and bootstrapping techniques. Results show that productivity growth has occurred, mainly due to improvement in production possibilities, and that mean efficiency has remained fairly constant over time. The bootstrap analysis yields further evidence, as for many firms productivity growth, or decline, is not statistically significant. With regard to efficiency measurement, the bootstrap reveals that the disparities in the original efficiency scores of some firms are lessened to a great extent.     

Financing reform and productivity change in Brazilian teaching hospitals: Malmquist approach

This study evaluates the performance and productivity changes for the Brazilian Federal University Hospitals, considering the years of 2003 and 2006, that is, before and after a 2004 financing reform. The analysis is based on the Malmquist index approach. Results indicate that the financing reform provided improvement in the technical efficiency, although the technological frontier has not presented a positive shift. This suggests that increased budgets were a good stimulus for efficiency but the intended enhancement of the technology through the financing reform has not yet taken place.     

我国农业上市公司融资效率研究——基于DEA模型和Malmquist指数法的实证分析

以我国农业上市公司2013-2017年的面板数据为样本,运用DEA模型和Malmquist指数法对不同金融成长周期的融资效率进行测度和分析.研究结果表明:农业上市公司的融资效率偏低,且大多数企业的综合效率表现为非有效;从不同金融成长周期阶段的融资效率来分析,其中大部分农业上市公司处于中年期,中年期的融资效率与农业上市公司整体融资效率的变化趋势相近,具有重要决定性作用;之后运用Malmquist指数方法从动态角度探究融资效率的变化,发现技术水平的降低是融资效率下降的重要原因.因此,进一步地提出提升农业上市公司融资效率的建议及措施.     

Structuring an MCDA model using SSM: A case study in energy efficiency

This work presents the use of a problem structuring method, Soft Systems Methodology (SSM), to structure a Multi-Criteria Decision Analysis (MCDA) model, aimed at appraising energy efficiency initiatives. SSM was useful to help defining clearly the decision problem context and the main actors involved, as well as to unveil the relevant objectives for each stakeholder. Keeney’s Value Focused Thinking approach was then used to refine and structure the list of objectives according to the perspective of the main evaluators identified. In addition to describing this particular case study, this paper aims at providing some general guidelines on how SSM may facilitate the emergence of objectives for MCDA models.     

中国能源强度与经济结构变化特征研究

中国经济持续增长伴随着能源强度下降的特征引起部分学者对中国经济增长和能源消费数据真实性的怀疑,因此,对中国能源强度变化特征进行研究具有重要的现实意义。迄今为止,对中国经济结构变动如何影响能源强度变化仍然缺少定量研究。本文分析了中国能源强度的变化趋势,说明其前后趋势基本上是一致、合理的。以此为基础,将能源强度变化分解为结构份额和效率份额,提出了结构份额和效率份额的计算方法,对我国能源强度变化中的结构份额和效率份额进行了定量分析,结构表明:1998-2000年间,我国能源强度下降的主要动力来自于各产业能源利用效率的提高,其中工业能源强度下降是总体能源强度下降的主要原因。     

The Indian auto component industry – Estimation of operational efficiency and its determinants using DEA

In this paper, the performance analysis of the Indian auto component industry is carried out from the perspectives of an original equipment manufacturer and a component supplier. Various efficiency measures are estimated using Data Envelopment Analysis with publicly available financial data on a representative sample of 50 firms. The first stage analysis reveals various operational inefficiencies in the auto component industry which are subsequently decomposed into technical, input mix and scale efficiencies. The study finds evidence that a majority of the inefficient firms are operating in the diminishing returns to scale region and demonstrates potential savings through benchmark input targets. A second stage analysis aimed at exploring root causes of inefficiencies finds that substitution of labour for capital could be causing a variety of inefficiencies including the input mix inefficiency in the Indian component industry. The empirical results also suggest that, unlike the global auto supply chain, higher average inventories are required for higher operational efficiencies in the Indian context. Contrary to the popular expectations, the technology licensing does not show significant influence on efficiency, at least in the short term, whereas efficient working capital management does result in higher operational efficiencies. The study also unearths the need to reform labour laws which are significantly contributing to various inefficiencies in the Indian component industry.     

Productive efficiency and energy use: An historical perspective

The paper discusses long-term trends in relationships between energy use and the overall productive efficiency of the American economy. While total energy consumption grew strongly during the twentieth century, the intensity of energy use (i.e. the energy/GNP ratio) fell persistently much of the time. Thus, there were simultaneous long-term improvements in labor productivity, total factor productivity,and energy productivity. The historical record appears to be at odds with conventional beliefs that gains in productive efficiency depend upon the rising intensity of energy use in production processes. A key role in bringing about these counter-intuitive results is assigned to what is referred to as the energy-technology-productivity nexus, in which the quality of particular energy forms such as electricity and liquid fuels (along with closely linked changes in energy-using technologies) played a critical part in leveraging the overall efficiency of production. As a result of these energy form-dependent improvements in productive efficiency, outputs grew more rapidly than all inputs, including the inputs of energy. The more recent past stands in sharp contrast to the long-term record. While energy efficiency (as measured by energy/GNP) showed strong gains during the late 1970's and early 1980's, the growth in overall productive efficiency was severely retarded. Implications for the future of suggested linkages between the quality of particular energy forms and technological progress are considered.     

A cooperative differential game model based on network throughput and energy efficiency in wireless networks

Network throughout and energy efficiency are of paramount importance for network performance in an energy-constrained wireless network. However, it is difficult to achieve optimal network throughout and energy efficiency simultaneously. So it is very necessary to find a solution based on tradeoff between network throughput and energy efficiency, which have not yet been well studied in existing works. In this paper, we present a cooperative differential game model and find a time-consistency solution by Shapley value which determines a fair distribution of the total cooperative cost among players.     

Unveiling endogeneity between competition and efficiency in Chinese banks: a two-stage network DEA and regression analysis

Although there is a growing number of research articles investigating the performance in the banking industry, research on Chinese banking efficiency is rather focused on discussing rankings to the detriment of unveiling its productive structure in light of banking competition. This issue is of utmost importance considering the relevant transformations in the Chinese economy over the last decades. This is a development of a two-stage network production process (production and intermediation approaches in banking, respectively) to evaluate the efficiency level of Chinese commercial banks. In the second stage regression analysis, an integrated Multi-Layer Perceptron/Hidden Markov model is used for the first time to unveil endogeneity among banking competition, contextual variables, and efficiency levels of the production and intermediation approaches in banking. The competitive condition in the Chinese banking industry is measured by Panar–Rosse H-statistic and Lerner index under the Ordinary Least Square regression. Findings reveal that productive efficiency appears to be positively impacted by competition and market power. Second, credit risk analysis in older local banks, which focus the province level, would possibly be the fact that jeopardizes the productive efficiency levels of the entire banking industry in China. Thirdly, it is found that a perfect banking competition structure at the province level and a reduced market power of local banks are drivers of a sound banking system. Finally, our findings suggest that concentration of credit in a few banks leads to an increase in bank productivity.

     

Estimating output allocative efficiency and productivity change: Application to Japanese banks

A new measure of output allocative efficiency is developed by comparing the input technical efficiency of a firm for the direct input requirement set and the indirect input requirement set proposed by Shephard [Indirect Production Functions, Verlag Anton Hain, Meisenheim Am Glan]. The ratio of the direct and indirect input quasi-distance functions serves as the measure of output allocative efficiency. As such, it measures the ratio of potential to actual inputs if the firm had chosen the revenue maximizing output mix. Using panel data on Japanese banks operating during 1992–1996 productivity growth is measured and decomposed into changes in output allocative efficiency, changes in input technical efficiency, and technical change. During the period, Japanese banks experienced productivity declines averaging 2% per year and could have used only 78–93% of actual inputs if they had chosen the revenue maximizing output mix.     

Integrated data envelopment analysis and cooperative game for evaluating energy efficiency of transportation sector: a case of Iran

Annals of Operations Research - Transportation sector with the consumption of 25% of energy play a major role in Iranian economy. This sector produces 27% of total undesirable greenhouse gases in...     

Unsupervised extreme learning machine and support vector regression hybrid model for predicting energy commodity futures index

Support vector regression (SVR) has been successfully applied in various domains, including predicting the prices of different financial instruments like stocks, futures, options, and indices. Because of the wide variation in financial time-series data, instead of using only a single standard prediction technique like SVR, we propose a hybrid model called USELM-SVR. It is a combination of unsupervised extreme learning machine (US-ELM)-based clustering and SVR forecasting. We assessed the feasibility and effectiveness of this hybrid model using a case study, predicting the one-, two-, and three-day ahead closing values of the energy commodity futures index traded on the Multi Commodity Exchange in India. Our experimental results show that the USELM-SVR is viable and effective, and produces better forecasts than our benchmark models (standard SVR, a hybrid of SVR with self-organizing map (SOM) clustering, and a hybrid of SVR with k-means clustering). Moreover, the proposed USELM-SVR architecture is useful as an alternative model for prediction tasks when we require more accurate predictions.     

Complex random energy model: zeros and fluctuations

The partition function of the random energy model at inverse temperature $\beta $ is a sum of random exponentials $ \mathcal{Z }_N(\beta )=\sum _{k=1}^N \exp (\beta \sqrt{n} X_k)$ , where $X_1,X_2,\ldots $ are independent real standard normal random variables (=random energies), and $n=\log N$ . We study the large N limit of the partition function viewed as an analytic function of the complex variable $\beta $ . We identify the asymptotic structure of complex zeros of the partition function confirming and extending predictions made in the theoretical physics literature. We prove limit theorems for the random partition function at complex $\beta $ , both on the logarithmic scale and on the level of limiting distributions. Our results cover also the case of the sums of independent identically distributed random exponentials with any given correlations between the real and imaginary parts of the random exponent.     

江苏-西部能源需求-供给模型及其动力学分析

根据江苏省能源需求与西部能源供给及江苏省能源进口量之间相互支持、相互制约的复杂关系建立了江苏-西部能源需求-供给系统．分析了系统的稳态、周期、分叉、混沌等若干动力学行为．通过调节参数可以使系统处于稳定发展或周期震荡区域中．基于Silnikov定理,应用待定系数法,求出了能源系统的同宿轨的表达式．证明了在两个平衡点处均有Silnikov型的同宿轨．根据Silnikov定理确保了能源系统有Smale马蹄和马蹄形混沌．     

Technical efficiency and economies of scale: A non-parametric analysis of REIT operating efficiency

This study measures technical efficiency and economies of scale for real estate investment trusts (REITs) by employing data envelopment analysis (DEA), a linear-programming technique. Using data from the National Association of Real Estate Investment Trusts (NAREITs) for the years 1992–1996, we find that REITs are technically inefficient, and the inefficiencies are a result of both poor input utilization and failure to operate at constant returns to scale. With respect to scale inefficiency, most REITs are operating at increasing returns to scale, suggesting that REITs could improve performance through expansion. Moreover, we employ regression analysis to determine what characteristics influence the efficiency measures obtained. The results show that internal REIT management is positively related to all measures of efficiency. Increasing leverage is negatively related to REIT input utilization. Finally, increasing REIT diversification across property types enhances scale efficiency (SE) but reduces input usage efficiency.     

Reimbursement systems and regional inpatient allocation: a non-linear optimisation model

^** Email: marion.rauner{at}univie.ac.at^*** Email: georg.schneider{at}univie.ac.at^**** Email: kurt.heidenberger{at}univie.ac.at This study presents a non-linear optimisation model for investigatingthe optimal allocation of both budgets and inpatients with differenttreatments among hospitals within a geographic region such asVienna. The objective function maximises the overall qualityof treatment provided by regional hospitals. We compare theeffects of two different reimbursement systems—fixed versusvariable budgets—on optimal allocation strategies. Thecombination of modelling ideas from hospital location-allocationmodels and economic models to solve such a problem is new accordingto the literature. We found that fixed budgets outperformedvariable budgets as fewer Euros had to be invested for an incrementalunit of quality of care provided in most of the policy scenariosanalysed. Regional demand and supply patterns for differenttreatments affect the decision makers' choice of the most suitablereimbursement system. In our illustrative example, two hospitalsappeared inefficient regardless of the reimbursement system.Vienna policy makers are currently considering restructuringthese hospitals. They plan to merge one with nearby hospitalsand transform the other into a nursing home.     

动态传播率模型及其在疫情分析中的应用

应用数据驱动的动态传播率来代替基本传染数$R_0$,在全国和省市两个层面上研究COVID-19疫情发展的特点和趋势。首先,基于动态增长率建立传染病常微分方程,推导得出动态传播率模型。其次,选择幂函数作为动态传播率的拟合函数,以3天作为最优滑窗期,对各地拐点进行了估计。最后,通过动态模型对各地不同程度尾声开始的起点进行了预测,并在13个省市间进行9个疫情相关指标的对比分析。结果显示,各地动态传播率在经过短暂的波动后均稳步下降,疫情得到有效控制;估计的拐点主要集中在2月中旬,而预测的尾声都将在3月底之前到来;同时,各地疫情发展特点和趋势、防控措施力度和效果存在一定差异。