In recent years, there has been growing interest in measuring the environmental efficiency of the different territories, countries, and/or nations. This has led to the development of different methods applied to the evaluation of environmental efficiency such as the data envelopment analysis (DEA) method. This method, supported by different studies, allows measuring relative environmental efficiency (eco-efficiency) and is consolidated as a very reliable method to measure the effectiveness of environmental policies in a specific geographical area. The objective of our study is the calculation of the environmental efficiency of the 28 member countries of the European Union (UE) through the DEA method. We will collect the data regarding the last years in which there are reliable comparative data in all. We will study in reference to them, the results of the environmental policies applied in the different countries, in order to make comparisons between countries and classify them according to their environmental efficiency. Using this, two variants of calculation within the DEA method to compare in a contrasted way the results of environmental efficiency for the 28 countries of the EU analyzed and propose possible solutions for improvement. Contributing in this work as main novelty the application of a new variant of the DEA method, which we will call improved analysis method (MAN) and that aims to agglutinate and assess more objectively, the results of the two DEA methods applied. The results show that there are 14 of the 28 countries that have a high relative environmental efficiency. However, we also find countries with very low environmental efficiency that should improve in the coming years. Coinciding precisely in this last group with countries recently admitted to the EU and where environmental policies have not yet been applied effectively and with positive results.
Keywords: CO2 emissions; DEA method; Economy; Environmental efficiency; Sustainable development; Undesirable outputs.