Progress toward eco-efficiency in Denmark, France, Germany, Luxembourg and The Netherlands, which share similar socio-economic standards, can be measured by a Malmquist productivity index approach to data-envelopment analysis (MDEA). In addition, an Environmental Kuznets Curve (EKC) was utilized to decouple analysis of per capita carbon dioxide (CO₂) emissions and Gross Domestic Product (GDP).
The Malmquist analysis revealed that Denmark and Luxembourg are leading countries, with rising averages of total factor productivity change (TFPCH) of 4.3% and 7.7% from 1990 to 2017, respectively. The lowest eco-efficiency improvement was shown in The Netherlands, with a 1.8% TFPCH. Technical efficiency change (TECHCH) and efficiency change (EFFCH) stood at 3.7% and -0.2%, respectively, indicating that the major contributor TFPCH was TECHCH. These values show that technological elements are the predominant contributor to enhanced TFPCH. However, efficiency trends appear to bring fewer positive contributions to TFPCH improvement, implying a failure to maximize outputs or minimize inputs during the study period.
The average Malmquist index for each nation can reveal the annual change of each nation. TFPCH was the highest in Luxembourg and TECHCH contributed the most to TFPCH growth in Luxembourg. Denmark, which had the second highest TFPCH, also experienced a change due to TECHCH. Luxembourg, followed by Denmark and Germany, maintained efficiency improvements in TFPCH and in all decomposed factors from 1990 to 2017. The Netherlands and France's EFFCH and scale efficiency change (SECH) declined, indicating that changes in scale and productivity of inputs were inefficient in both countries.
Application of the EKC demonstrated that Denmark has made significant steps toward eco-efficiency and is shifting to a post-industrial economy. France which has the lowest GDP per capita among the countries is closer to the point of origin of the curve stating that the per capita CO₂ emissions is also low. Germany, Denmark, and The Netherlands stood out in this group of countries as the period from 1990-2017 shows the latter half of their inverse U-shaped curve indicating a strong decoupling trend. Contrary to the above countries, Luxembourg's data show strong fluctuations in terms of eco-efficiency. It is to be noted that theoretically, Luxembourg can be considered as the country with the highest potential to reach a post-industrial economy as it has the smallest population and therefore the lowest total energy consumption signifying reducing CO₂ emissions.
The chronological policy analysis of the chosen countries provides an understanding of the informed decisions on green growth and low-carbon emissions made in these countries through eco-industrial park programs and other techniques that are focused on attaining sustainability. Overall, improvements in efficiency in developed countries with respect to resource consumption and cleaner production methods can provide examples for developing countries to follow.