Mapping socio-environmental policy integration in the European Union: A multilayer network approach

This paper faces the relevant task of assessing the integration of European countries when dealing with three paradigmatic socio-environmental themes: Circular Economy (CE), Energy Transition (ET), and Social Justice (SJ). Specifically, we aim to explore whether a similar behavior in facing one of the considered aspects is mirrored by similarity in the others. We move from a dataset composed of five variables for CE, two for ET, and three for SJ, representing yearly data for the quinquennium 2016-2020 and European countries. We build a multilayer network based on the ten variables having countries as nodes. Each layer/variable has weighted links based on countries' similarity. Inter-layer links are created through a community detection exercise over the individual layers. This approach allows us to evaluate analogies, leading to the assessment of intra- and inter-layer policy integration. We find a relatively low level of integration at the European level and a high sensitivity to the number of detected communities, thus revealing the role of countries' heterogeneity in driving integration.