Efficiency Driver in Nigerian Airports: A Bootstrap DEA–Censored Quantile Regression Approach

This paper reports on the use of a novel two-stage approach for assessing the efficiency of 30 major Nigerian airports from 2003 to 2013 based on bootstrapped data envelopment analysis (DEA) and censored quantile regression. In the first stage, bootstrapped efficiency estimates are computed. They enable bias correction and testing for significant differences in efficiency levels among airports. Subsequently, bootstrapped DEA results are combined with censored quantile regression to assess the impact of contextual variables—related to the airports’ ownership, location, and network connectivity—on different efficiency percentiles. The results reveal that the intensity of significant impacts regarding airports’ contextual variables may vary between high-/low-efficiency airports. Policy implications are derived accordingly

Computing confidence intervals for output oriented DEA models: an application to agricultural research in Brazil.

We define and model the research production at Embrapa, the major Brazilian institution responsable for applied agricultural research. The main theoretical framework is Data Envelopment Analysis - DEA. We explore the economic interpretation and the statistical properties of these models to compute confidence intervals for output oriented efficiency measurements, based on a parametric flexible model, defined by the truncated normal distribution. These results provide a better insight on the efficiency classification and allow comparison among the DMUs involved int ehe evaluation process taking into account inefficiency random variation

Confidence intervals for DEA efficiency measurements applied to Embrapa´s research system: a bootstrap approach.

Neste artigo foi estudado o sistema de produção de pesquisa da Embrapa, a maior instituição brasileira de pesquisa agropecuária. A principal ferramenta teórica usada foi a Análise de Envoltória de Dados – DEA. Exploraram-se a interpretação econômica e as propriedades estatísticas desses modelos, para calcular intervalos de confiança para medidas de eficiência orientadas a output. Tomou-se como base um modelo paramétrico flexível, definido pela distribuição normal truncada. Os intervalos foram calculados por reamostragem. Estes resultados geraram melhores entendimentos sobre as medidas de eficiência e permitiram comparações entre as DMUs envolvidas na análise. O modelo considerou erros de ineficiência e erros aleatórios

Advancing efficiency analysis using data envelopment analysis: the case of German health care and higher education sectors

The main goal of this dissertation is to investigate the advancement of efficiency analysis through DEA. This is practically followed by the case of German health care and higher education organizations. Towards achieving the goal, this dissertation is driven by the following research questions: 1.How the quality of the different DEA models can be evaluated? 2.How can hospitals’ efficiency be reliably measured in light of the pitfalls of DEA applications? 3.In measuring teaching hospital efficiency, what should be considered? 4.At the crossroads of internationalization, how can we analyze university efficiency? Both the higher education and the health care industries are characterized by similar missions, organizational structures, and resource requirements. There has been increasing pressure on universities and health care delivery systems around the world to improve their performance during the past decade. That is, to bring costs under control while ensuring high-quality services and better public accessibility. Achieving superior performance in higher education and health care is a challenging and intractable issue. Although many statistical methods have been used, DEA is increasingly used by researchers to find best practices and evaluate inefficiencies in productivity. By comparing DMU behavior to actual behavior, DEA produces best practices frontier rather than central tendencies, that is, the best attainable results in practice. The dissertation primarily focuses on the advancement of DEA models primarily for use in hospitals and universities. In Section 1 of this dissertation, the significance of hospital and university efficiency measurement, as well as the fundamentals of DEA models, are thoroughly described. The main research questions that drive this dissertation are then outlined after a brief review of the considerations that must be taken into account when employing DEA. Section 2 consists of a summary of the four contributions. Each contribution is presented in its entirety in the appendices. According to these contributions, Section 3 answers and critically discusses the research questions posed. Using the Translog production function, a sophisticated data generation process is developed in the first contribution based on a Monte Carlo simulation. Thus, we can generate a wide range of diverse scenarios that behave under VRS. Using the artificially generated DMUs, different DEA models are used to calculate the DEA efficiency scores. The quality of efficiency estimates derived from DEA models is measured based on five performance indicators, which are then aggregated into two benchmark-value and benchmark-rank indicators. Several hypothesis tests are also conducted to analyze the distributions of the efficiency scores of each scenario. In this way, it is possible to make a general statement regarding the parameters that negatively or positively affect the quality of DEA estimations. In comparison with the most commonly used BCC model, AR and SBM DEA models perform much better under VRS. All DEA applications will be affected by this finding. In fact, the relevance of these results for university and health care DEA applications is evident in the answers to research questions 2 and 4, where the importance of using sophisticated models is stressed. To be able to handle violations of the assumptions in DEA, we need some complementary approaches when units operate in different environments. By combining complementary modeling techniques, Contribution 2 aims to develop and evaluate a framework for analyzing hospital performance. Machin learning techniques are developed to perform cluster analysis, heterogeneity, and best practice analyses. A large dataset consisting of more than 1,100 hospitals in Germany illustrates the applicability of the integrated framework. In addition to predicting the best performance, the framework can be used to determine whether differences in relative efficiency scores are due to heterogeneity in inputs and outputs. In this contribution, an approach to enhancing the reliability of DEA performance analyses of hospital markets is presented as part of the answer to research question 2. In real-world situations, integer-valued amounts and flexible measures pose two principal challenges. The traditional DEA models do not address either challenge. Contribution 3 proposes an extended SBM DEA model that accommodates such data irregularities and complexity. Further, an alternative DEA model is presented that calculates efficiency by directly addressing slacks. The proposed models are further applied to 28 universities hospitals in Germany. The majority of inefficiencies can be attributed to “third-party funding income” received by university hospitals from research-granting agencies. In light of the fact that most research-granting organizations prefer to support university hospitals with the greatest impact, it seems reasonable to conclude that targeting research missions may enhance the efficiency of German university hospitals. This finding contributes to answering research question 3. University missions are heavily influenced by internationalization, but the efficacy of this strategy and its relationship to overall university efficiency are largely unknown. Contribution 4 fills this gap by implementing a three-stage mathematical method to explore university internationalization and university business models. The approach is based on SBM DEA methods and regression/correlation analyses and is designed to determine the relative internationalization and relative efficiency of German universities and analyze the influence of environmental factors on them. The key question 4 posed can now be answered. It has been found that German universities are relatively efficient at both levels of analysis, but there is no direct correlation between them. In addition, the results show that certain locational factors do not significantly affect the university’s efficiency. For policymakers, it is important to point out that efficiency modeling methodology is highly contested and in its infancy. DEA efficiency results are affected by many technical judgments for which there is little guidance on best practices. In many cases, these judgments have more to do with political than technical aspects (such as output choices). This suggests a need for a discussion between analysts and policymakers. In a nutshell, there is no doubt that DEA models can contribute to any health care or university mission. Despite the limitations we have discussed previously to ensure that they are used appropriately, these methods still offer powerful insights into organizational performance. Even though these techniques are widely popular, they are seldom used in real clinical (rather than academic) settings. The only purpose of analytical tools such as DEA is to inform rather than determine regulatory judgments. They, therefore, have to be an essential part of any competent regulator’s analytical arsenal

Efficiency in education. A review of literature and a way forward

This paper provides an extensive and comprehensive overview of the literature on efficiency in education. It summarizes the earlier applied inputs, outputs and contextual variables, as well as the used data sources of papers in the field of efficiency in education. Moreover, it reviews the papers on education that applied methodologies as Data Envelopment Analysis, Malmquist index, Bootstrapping, robust frontiers, metafrontier, or Stochastic Frontier Analysis. Based on the insights of the literature review, a second part of the paper provides some ways forward. It attempts to establish a link between the parametric 'economics of education' literature and the (semi-parametric) 'efficiency in education literature'. We point to the similarities between matching and conditional efficiency; difference-in-differences and metafrontiers; and quantile regressions and partial frontiers. The paper concludes with some operative directions for prospective researchers in the field

Environmental Efficiency and Regional Convergence Clusters in Japan: A Nonparametric Density Approach

This paper studies environmental efficiency convergence across the prefectures of Japan over the 1992-2008 period. Using a novel nonparametric density estimation clustering framework, two alternative indicators of environmental efficiency are contrasted: a conventional indicator, based on the ratio of gross regional product to CO2 emissions, and a more comprehensive indicator, based on the data envelopment analysis (DEA) model. Results show, on the one hand, a lack of intra-distributional mobility and potentially a unique convergence cluster when using the more conventional indicator. On the other hand, large backward mobility and at least two convergence clusters are identified when using the DEA-based indicator of environmental efficiency. The paper concludes arguing the importance of accounting for production inputs, as they appear to be driving the formation of regional convergence clusters in Japan