Cátedra Santander en Eficiencia y Productividad

Sorry, this entry is only available in European Spanish.

Sorry, this entry is only available in European Spanish.

Tittle: Combining metaheuristics with mathematical programming and machine learning

Speaker:  El-Ghazali Talbi  (University of Lille 1)

Date: 11/04/2017 12:30h

Location: Sala de Seminarios, Edificio Torretamarit

Abstract:

During the last years, interest on hybrid metaheuristics has risen considerably in the field of optimization and machine learning. The best results found for many optimization problems in science and industry are obtained by hybrid optimization algorithms. Combinations of optimization tools such as metaheuristics, mathematical programming, constraint programming and machine learning, have provided very efficient optimization algorithms. Four different types of combinations are considered in this talk: (i) Combining metaheuristics with complementary metaheuristics. (ii) Combining metaheuristics with exact methods from mathematical programming approaches which are mostly used in the operations research community. (iii) Combining metaheuristics with machine learning and data mining techniques.

Sorry, this entry is only available in European Spanish.

Sorry, this entry is only available in European Spanish.

Sorry, this entry is only available in European Spanish.

Sorry, this entry is only available in European Spanish.

Title: Efficiency and productivity of Portuguese municipalities after local reforms

Speaker: José Manuel Cordero

Date: 10/11/2016 11:00 h

Location: Sala de Seminarios, Edificio Torretamarit

Abstract:

The aim of this work is to examine the effect of the reforms introduced in the structure of the Portuguese local administration after the bailout agreement in 2011 on the efficiency and productivity of municipalities. Specifically, we assess the performance of the 278 Portuguese mainland municipalities for the recent six-year period 2009-2014. Firstly, in order to determine a measure of productivity change we apply the global Malmquist productivity index developed by Pastor and Lovell (2005), which allows determining productivity change over time. Subsequently, since we are aware that the performance of local governments might be affected by their socio economic context, we apply the conditional frontier estimators developed by Daraio and Simar (2005) adapted to a dynamic framework by Mastromarco and Simar (2015). Furthermore, thie technique allows us to examine the effect of contextual and exogenous variables on municipal efficiency levels and technological change. The results reveal that the recent local reforms have had a positive effect on the productivity of municipalities, but only for small and medium-sized municipalities.

Brief Bio:

He is an Associate Professor in the Department of Economics in the University of Extremadura. He holds a degree and Ph.D. in Economics from the same university. His scientific production has been focused in the following fields of research: efficiency measurement in the public sector, economics of education and fiscal federalism, including local and regional governments. His research experience in the aforementioned fields has been reflected in multiple scientific articles published in referred journals as well as in several books and book chapters. He was a visiting scholar in Teachers College de Columbia University with the funds provided by the Spanish Ministry of Science and Education. He has participated as principal researcher or as a member of the research group in multiple research projects from different entities (Ministry of Economy and Competitiveness, Extremadura Government, Ramón Areces Foundation or the Institute for Fiscal Studies). Likewise, he has attended numerous conferences and congresses in Spain and worldwide related to his research interests. Previously he occupied a position as a technical advisor for the President of the Provincial Government in Badajoz and the President of the National Comission of Local Governments integrated in the Spanish Federation of Municipalities and Provinces.

Title: Assessment of different approaches to incorporate contextual variables in efficiency measurement.

Speaker: Cristina Polo

Date: 10/11/2016 10:00h

Location: Sala de Seminarios, Edificio Torretamarit

Abstract:

Incorporating the effect of the exogenous variables into the estimation of efficiency measures is one of the issues that have received more attention in recent years within the operations research literature. The aim of this work is to assess the performance of two recently developed methodologies such as the nonparametric conditional model and the StoNEZD (Stochastic Nonparametric Envelopment on Z-variables Data) method, which combines both parametric and nonparametric techniques. To do this, we conduct a Monte Carlo experiment with various alternatives production functions. According to the results, StoNEZD methodology performs better, although the conditional DEA model also provides acceptable results in all the proposed scenarios, thus it can be considered as a valid alternative when the available data cannot be adapted to the specific framework of the StoNEZD model.

Brief Bio:

She has a degree in Physics by the University of Extremadura. He has a master’s degree in Social and Legal Sciences (specializing in Economics, Business and Labour). Her main research lines are focused on computational aspects related to efficiency measurement and its application in public services as diverse as education, health and municipal services. She has several publications in prestigious international journals and also she has participated as speaker at the most important meetings, nationals and internationals, which are related to efficiency and productivity measurement. Previously, she further developed research activities related to computational aspects in the Laboratory of Intelligent Sensory Systems (LSSI) of the UEx and the National Institute for Aerospace Technology (INTA) of the Ministry of Defense.

Title: Addressing the endogeneity issue in DEA applications

Speaker: Gabriela Sicilia

Date: 27/07/2016 12:00 h

Location: Sala de Seminarios, Edificio Torretamarit

Abstract:
The presence of the endogeneity is frequently observed in several economic production processes, however, it has received little attention in the frontier literature and it is overlooked when practitioners apply data envelopment analysis (DEA). Recently, Cordero, Santín and Sicilia (2015) concluded that when one input in the production process is highly and positively correlated with the true efficiency level, endogeneity arises and DEA estimates are flawed. In addition, they find that this decline in DEA performance is further driven by the misidentification of the most inefficient DMUs with low levels of the endogenous input. These findings take on greater significance since high positive endogenous scenarios are similar to those that are likely to be found in many production processes. In this context, the estimation of the technical efficiency using DEA models without taking into account the presence of endogeneity leads to inaccurate efficiency estimates where many of the most inefficient DMUs are identified as benchmarks, which will lead to inappropriate performance-based recommendations. Building upon this evidence, in this research we address two key issues: how can we detect the presence of an endogenous input? And, how can we deal with this problem in DEA empirical applications to overcome this problem and improve estimations? First, we provide a simple heuristic procedure which allows practitioners to identify the presence of an endogenous input in an empirical research. Second, we propose the use of an instrumental input DEA (II-DEA) as a potential solution to deal with the endogeneity problem in order to improve DEA estimations. Monte Carlo results confirm that II-DEA approach outperforms standard DEA when an input has a high a positive correlation with the technical efficiency. Finally, we perform an empirical application to illustrate our theoretical findings.

Brief Bio:
Ph.D. in Economics at Complutense University of Madrid (2015). Her main lines of research are the measurement of efficiency and productivity and causal inference applied to the field of education, combining both methodological and applied elements. Her work has led to several publications in scientific international journals such as the European Journal of Operational Research, Scientometrics, Pacific Economic Review, Latin American Economic Review and The Social Science Journal and have been discusssed in more than 20 national and international conferences and workshops. She has also participated in several competitive research projects and is a regular contributor to the European Foundation Society and Education.