The aim of the paper is to examine the long-term relationship between economic complexity, energy consumption structure, and greenhouse gas emission, within a panel of European Union countries and two subpanels: (i) European economies with higher economic complexity and (ii) European economies with a lower level of economic complexity. Taking into consideration the heterogeneity among European countries, the heterogeneous panel technique is used, including panel estimation through fully modified least squares (FMOLS) and dynamic ordinary least squares (DOLS). The empirical findings indicate a long-term equilibrium relationship between economic complexity, energy consumption structure and greenhouse gas emission within all three panels. Economic complexity and energy consumption structure have a statistically significant impact on greenhouse gas emission within all panels, but the influence is higher within the subpanel of countries with a lower level of economic complexity, suggesting a higher risk of pollution as the economic complexity grows and as the energy balance inclines in favor of non-renewable energy consumption. Our paper suggests that the economic complexity is a variable that must be taken into consideration when national economic and energy policies are shaped. Finally, policy implications for each panel of countries are discussed.

The aim of the paper is to apply the Environmental Kuznets Curve (EKC) model in order to explore the link between economic complexity index (ECI) and carbon emissions, in 25 selected European Union (EU) countries from 1995–2017. The study examines a cointegrating polynomial regression (CPR) for a panel data framework as well as for simple time series of individual countries. In the model is also included the variable ‘energy intensity’ as main determinant of carbon emissions. Depending on economic complexity, the CO2 emissions pattern was found to exhibit an inverted U-shaped curve: in the initial phase, pollution increases when countries augment the complexity of the products they export using and after a turning point the rise of economic complexity suppress the pollutant emissions. The panel cointegration test indicates a long-run relationship between economic complexity, energy intensity and carbon emissions. It was also found that a rise of 10% of energy intensity would lead to a 3.9% increase in CO2 emissions. The quadratic model incorporating ECI is validated for the whole panel as well as for six countries (Belgium, France, Italy, Finland, Sweden and the United Kingdom). The graphical representation of the EKC in these countries is discussed. Policy implications are also included.

The paper introduces economic complexity as an explanatory variable of ecological footprint change, along with income per capita and fossil fuel energy consumption. The link between the ecological footprint and economic complexity is explored within a panel of 48 complex economies over the period 1995–2014. The panel analysis is based on the annual data series of the economic complexity index (ECI), fossil fuel energy consumption, income per capita, and the ecological footprint of production. The econometrical analysis, based on second-generation unit root tests, cointegration testing, and estimation of fully modified ordinary square (FMOLS) and dynamic ordinary least square (DOLS) models in a heterogeneous panel of countries, revealed a validated positive long-run association between the ecological footprint of production as dependent variable and the economic complexity index, gross domestic product per capita, and fossil fuel energy consumption. The paper sheds light on the critical situation of environmental sustainability, taking into consideration that 75% of countries under examination are in ecological deficit.