Halkos, George E.; Tzeremes, Nickolaos G. - In: Economics Letters 120 (2013) 1, pp. 48-52
inverted ‘U’ shape relationship between regional environmental efficiency and per capita income. The results derived from a non … environmental efficiency and GDP per capita levels. As an illustrative example we apply our model to US regional data revealing an …This paper proposes a conditional directional distance function estimator in order to examine the link between regional …