Examining the drivers of total factor productivity change with an illustrative example of 14 EU countries

Based on the different models developed by Korhonen and Luptacik [Korhonen, P., Luptacik, M., 2004. Eco-efficiency analysis of power plants: An extension of data envelopment analysis. European Journal of Operational Research 154, 437–46], this contribution centers on the development of an intertemporal comparison in order to analyze eco-efficiency change over time. In this setup two model variants by Korhonen and Luptacik (2004) are used in order to provide deeper insights concerning the driving forces for the change in the eco-efficiency. Which bias in technical change can be observed? Is it more input-saving or pollution-reducing? For illustration purposes the proposed approach is used to analyze the performance of 14 countries of the European Union for the period 1995–2004. An average eco-productivity growth of 22% is observed. The estimated contribution of improved use of input is 20% and that of reduced relation of greenhouse gas emissions is 23%. Therefore it is concluded that, on average, the eco-productivity growth is more driven by improved environmental conditions.