By asserting a sociological ambition enriched with an economic viewpoint, the PADAC project proposes to study in real time over a four-year period the emergence of digital platforms in the agricultural sector, the dynamics of collective action and the resulting changes in work organisation. More and more traditional sectors are being pushed by the emergence of digital platforms, so that some authors do not hesitate to talk about platform capitalism (Srnicek, 2017). The latter challenge the traditional forms which frame exchanges and regulate markets. While this observation is shared, there is little work that analyses the development of platforms and the controversies they generate at the level of an economic sector. The ambition of the PADAC research project is to study to what extent the emergence of digital platforms in an economic sector - the agricultural sector - contributes to redefining the dimensions of collective action and institutional dynamics. Indeed, while for nearly a century the agricultural sector has been deeply structured by professional agricultural organizations based on the principles of collective action, the ability of digital agricultural platforms to profoundly challenge them and to regulate this sector economically and politically raises questions. These platforms compete with the traditional professional organisations to which the State has entrusted political and economic regulatory tools and thus disrupt the political organisation of this sector. They raise the question of regulating this sector in which the financial logic of platforms is opposed to the political logic of traditional organizations. By combining qualitative and quantitative methods will show the complexity of platforms’ institutional work imply to study at the same time multilevel networks involving them, how agricultural actors use these new tools, as well as normative choices in regulatory controversies of all of these actors at different levels. So this project is composed by three different but interrelated scales. At the scale of the agricultural sector, we will study the dynamics of alliances and oppositions between platforms and professional agricultural organizations. This will allow us to explore the regulatory process by articulating normative and structural positions. We assume that platforms and takeover bids weave relationships of both competition and alliance, in order to build new modalities for the framework of the agricultural profession and institutional coexistence. At the level of the platforms themselves, we will analyse the various dissemination and development strategies they put in place as well as the instruments and methods they mobilise to establish their legitimacy within the agricultural profession and public authorities. The fundamental question is to understand the long-term regulation of this sector, by identifying the models that can spread and become standards. At the level of farmers and their farms, we will study the use they make of digital platforms. The aim will be to understand to what extent the use of platforms changes farmers' practices and how farmers update or not the new rules of action and coordination carried by the platforms. Keywords : Digital platforms ; Institutionalization ; Collective action ; Agricultural sector ; Social Networks ; Uses