This paper proposes a conditional directional distance function model in order to examine the link between regional environmental efficiency and GDP per capita levels. As an illustrative example we apply our model to USA regional data revealing an inverted ‘U’ shape relationship between...

This paper by applying a directional distance function approach measures the UK regions’ municipality waste performance. In addition the paper constructs conditional stochastic kernels trying to determine nonparametrically the association of regions’ GDP per capita levels with their...

Economic activity produces not only desirable outputs but also undesirable outputs that are usually called negative externalities in economic theory. Negative externalities are usually omitted from efficiency assessments (i.e., applications of Data Envelopment Analysis) which fail to express the...

This paper applies a data envelopment analysis (DEA) method to assess technical efficiency of both private and public universities in Italy. Moving from the traditional context where inputs and outputs are assumed to be non-negative, a directional distance function approach has been applied in...

The directional distance function model is a generalization of the radial model in data envelopment analysis (DEA). The directional distance function model is appropriate for dealing with cases where undesirable outputs exist. However, it is not a units-invariant measure of efficiency, which...

This paper, by using conditional directional distance functions as introduced by Simar and Vanhems [J. Econometrics 166 (2012) 342-354] modifies the model by Färe and Grosskopf [Eur. J. Operat. Res. 157 (2004) 242-245], examines the link between regional environmental efficiency and economic...