Efficiency analysis of public environmental protection expenditures: The example of OECD countries

Environmental protection expenditures are the primary tools used by the public in combating environmental problems. This study aims to determine the factors that determine the efficiency scores obtained by calculating the efficiency of public environmental protection expenditures on selected environmental indicators. The study's data set consists of environmental data from 30 OECD countries between the years 2008-2020. Two-stage data envelopment analysis was used as a method in the study. The data envelopment analysis super efficiency model was used in the first stage of the analysis. In the data envelopment analysis, the public environmental protection expenditures of the countries were used as inputs; carbon dioxide emissions, renewable energy production, forest areas, and particulate matter rates in the air were used as outputs. In the second stage of the analysis, a classical panel data analysis was applied, in which the efficiency scores obtained were used as dependent variables. In the panel data analysis, the population density, urbanization, industrialization, per capita national income, and primary energy density data of the countries were used as independent variables. According to the analysis results, it was observed that there was a negative relationship between the efficiency scores of OECD countries and their population densities and primary energy densities, and a positive relationship between urbanization and industrialization. No relationship was found between per capita national income and efficiency scores. According to these results, urbanization and industrialization increase the effectiveness of countries' environmental protection expenditures.