The purpose of this research paper is to investigate and identify the factors which can support the development of one characteristic of smart cities, namely, the smart environment. More specifically, the main goal is to measure the extent to which air pollution may be reduced, taking as determinants several circular economy, fiscal, and environmental factors. The Ordinary Least Squares, the Fixed Effects, and Random Effects regression models using balanced panel data were employed, over the 2011–2019 period, for 28 European states. After rigorously studying the literature, 11 indicators with a predictable impact on the exposure to air pollution were kept. According to current analysis, the most effective methods of reducing air pollution are the use of renewable energy, the investments in educating the population to reduce pollution, the proper implementation of the circular economy, and the adoption of the most suitable policies by the European Union governments. Particular attention needs to be paid to factors such as carbon dioxide-generating activities, which are significantly increasing the air pollution. Another strong value is that of providing information on the assessment of ambient air quality, and on the promotion of appropriate policies to achieve two major objectives: well-being, and sustainable cities.

This paper assesses education sector’s efficiency by comparing 28 European Union states at different levels of education using the mathematic approach of data envelopment analysis. We conducted the study from both the allocative and technical perspectives by considering all education levels separately and then as a whole, every three years, starting with 2006. The input and output variables were adapted to each particular level of education. In this way, we offered a complete image of the education system, creating a ranking for the countries, based on efficiency scores. Efficiency appears to be achieved when education results, such as the Programme for International Student Assessment scores, attainment level or other value-added outcomes, are reached with rather low levels of financial resources. The performance in education lacks sustainability in many countries, mostly belonging to Mediterranean and south-eastern European groups, with old member states recording efficiency scores closer to 1 compared to the new ones. Inefficiency derived from different causes and interactions between these causes (the mixture between public and private resources, the different population composition, gross domestic product per capita or levels of education attainment) and most often imply particular solutions from country to country.