A Meso-Level Perspective on the Social and Solidarity Economy: Towards a New Paradigm?[L’approche méso de l’économie sociale et solidaire : vers un nouveau paradigme ?]

This thematic issue is devoted to the meso‑level approach to the social and solidarity economy (SSE), at a time when ecological, social, political, and economic crises are reinforcing the relevance of the SSE as a space for socio‑ecological transition. This introduction reminds us that although the SSE is recognized for its potential to transform capitalism, it remains marked by significant tensions—declining public funding, marketization, and inequalities—that hinder its scaling up. The meso approach, derived from regulation theory, offers an intermediate level of analysis that connects organizational dynamics, collective arenas, institutional arrangements, and macroeconomic developments. It highlights meso spaces—networks, sectors, territories, and movements—in which forms of inter‑cooperation and alternative productive models are built. This analytical framework identifies four channels of differentiation: internal competition within capital, capital–labor relations, futurity, and the relationship to nature, which structure and differentiate SSE dynamics. This issue, composed of 10 articles, 2 cross‑interviews, and 2 book reviews, explores cooperative models, diverse sectors, and collective actors, while questioning the capacity of the meso approach to constitute a new paradigm for understanding the social and ecological transformation driven by the SSE. It also proposes several research avenues to further develop this emerging perspective.