http://repub.eur.nl/res/aut/241/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/14062/ 2007-01-01T00:00:00Z We develop a non-parametric test of productive efficiency that accounts for errors-in-variables, following the approach of Varian. [1985. Nonparametric analysis of optimizing behavior with measurement error. Journal of Econometrics 30(1/2), 445–458]. The test is based on the general Pareto–Koopmans notion of efficiency, and does not require price data. Statistical inference is based on the sampling distribution of the L∞ norm of errors. The test statistic can be computed using a simple enumeration algorithm. The finite sample properties of the test are analyzed by means of a Monte Carlo simulation using real-world data of large EU commercial banks. http://repub.eur.nl/res/pub/6203/ 2004-07-01T00:00:00Z This paper explores an intermediate route between the Fisher and the Malmquist productivity indexes so as to minimize data requirements and assumptions about economic behavior of production units and their production technology. Assuming quantity data of inputs and outputs and the behavioral hypothesis of allocative efficiency, we calculate the exact value of the Fisher ideal productivity index using implicit shadow prices revealed by the choice of input?output mix. The approach is operationalized by means of a nonparametric data envelopment analysis (DEA) model. Empirical application to Finnish grass silage farms suggests that the Malmquist and the Fisher productivity indices yield similar results when averaged over firms, but there can be major differences in the results of the two approaches at the level of individual firms. http://repub.eur.nl/res/pub/14124/ 2003-01-16T00:00:00Z This note identifies and corrects a technical error in T. Kuosmanen, G.T. Post, Eur. J. Oper. Res. 134 (2001) 43–58. http://repub.eur.nl/res/pub/6201/ 2003-01-01T00:00:00Z This note identifies and corrects a technical error in T. Kuosmanen, G.T. Post, Eur. J. Oper. Res. 134 (2001) 43?58 http://repub.eur.nl/res/pub/6196/ 2002-12-11T00:00:00Z We extend the non-parametric methodology for empirical production analysis to deal with endogenous prices. As price endogeneity is often complemented by price uncertainty, we consider both the case of certain prices and the case of uncertain prices. The extensions are fully compatible with existing tools for eliciting and representing technology and price information, and preserves the tractable mathematical programming structure of the original methodology. An empirical application to the Dutch electricity distribution sector illustrates our extension. http://repub.eur.nl/res/pub/6202/ 2002-11-01T00:00:00Z Data Envelopment Analysis (DEA) offers a piece-wise linear approximation of the production frontier. The approximation tends to be poor if the true frontier is not concave, eg in case of economies of scale or of specialisation. To improve the flexibility of the DEA frontier and to gain in empirical fit, we propose to extend DEA towards a more general piecewise http://repub.eur.nl/res/pub/6191/ 2002-08-01T00:00:00Z This paper develops a new nonparametric model for efficiency estimation. In contrast to Data Envelopment Analysis (DEA), it does not impose debatable production assumptions like free disposability and convexity, and it does not assume that the data are measured without error. The estimators are asymptotically unbiased and have an asymptotic variance that is comparable to that of stochastic frontier estimators (provided the latter use a correct specification of the functional form for the production relationships). In addition, the estimators can be computed using a simple enumeration algorithm. http://repub.eur.nl/res/pub/6199/ 2002-05-01T00:00:00Z This paper extends the nonparametric approach to efficiency analysis to deal with uncertainty of input-output prices.We generalize the notion of economic efficiency to derive necessary and sufficient first-order stochastic dominance (FSD) efficiency conditions. Interestingly, the FSD conditions include as limiting cases the traditional conditions for economic efficiency and technical efficiency. Furthermore, we propose empirical tests for these FSD http://repub.eur.nl/res/pub/6194/ 2001-10-01T00:00:00Z We extend Free Disposable Hull (FDH) efficiency analysis towards the general directional distance function framework. The profit interpretation of directional distance functions is extended to the non-convex FDH technologies. In addition, we derive an efficient enumerative algorithm for computing distance measures in Free Disposable Hull (FDH) technologies, which applies to the entire (infinitely large) family of directional distance functions. A simple numerical example and an application to European commercial banks illustrate the algorithm. http://repub.eur.nl/res/pub/6200/ 2001-10-01T00:00:00Z Measuring economic efficiency requires complete price information, while resorting to technical efficiency exclusively does not allow one to utilise any price information. In most studies, at least some information on the prices is available from theory or practical knowledge of the industry under evaluation. In this paper we extend the theory of efficiency measurement to accommodate incomplete price information by deriving upper and lower bounds for Farrell's overall economic efficiency. The bounds typically give a better approximation for economic efficiency than technical efficiency measures that use no price data whatsoever. From an operational point of view, we derive new data envelopment analysis (DEA) models for computing these bounds using standard linear programming. The practical application of these estimators is illustrated with an empirical application to large European Union commercial banks. http://repub.eur.nl/res/pub/6195/ 2001-07-01T00:00:00Z This paper is a response to Cooper, W.W., B. Gu, and S. Li: `Comparisons and Evaluations of Alternative Approaches to the Treatment of Congestion in DEA', European Journal of Operational Research (this issue), who claim that the standard FGL procedure by Färe, Grosskopf, and Lovell for dealing with congestion in DEA can (i) fail to identify congestion when it is present, and (ii) identify congestion when it is not present. We clarify the notion of congestion, and its relationship to structural efficiency and free disposability respectively, to point out that the FGL approach was originally intended for measuring structural efficiency, i.e. the in�uence of congestion on the efficiency of a particular production unit, not for identifying occurrence of congestion in any feasible production vector. Moreover, we point out that the result of Cooper et al. partially arises from ignorance of some key maintained assumptions underlying the FGL approach. Further, we present some counter-examples which demonstrate that the alternative approach advocated by Cooper et al. can equally fail in identification of congestion. Finally, some remarks on the influence of sampling error and errors-in-variables on the two-stage DEA approaches are presented http://repub.eur.nl/res/pub/88/ 2001-04-19T00:00:00Z We develop a nonparametric test of productive efficiency that accounts for the possibility of errors-in-variables. The test allows for statistical inference based on the extreme value distribution of the L?? norm. In contrast to the test proposed by Varian, H (1985): 'Nonparametric Analysis of Optimising Behaviour with Measurement Error, Journal of Econometrics 30, 445-458, our test can be computed using simple enumeration algorithms or linear programming. An empirical application for the Dutch electricity sector illustrates the proposed test procedure. http://repub.eur.nl/res/pub/72/ 2001-02-12T00:00:00Z This paper develops a novel statistic for firm efficiency called efficiency depth that allows for statistical inference in case of errors-in-variables. We derive statistical tests that require minimal statistical assumptions; neither the sample distribution nor the noise level is required. An empirical illustration for European banks illustrates that - despite the minimal assumptions- the tests can have substantial discriminating power in practical applications. http://repub.eur.nl/res/pub/6193/ 2000-05-01T00:00:00Z no