For some years now, public action has had to adapt to a number of changes in the habits and demands of service-users. Drawing on new methods and social innovations, this move toward modernization seems to be quite well advanced in France. By contrast, as Marjorie Jouen stresses here, when it comes to transforming public action because certain practices or services have ceased to meet the general interest or have become detrimental to the community, the state seems to have more difficulty adapting. However, the analysis of social change and its drivers offers new opportunities for public actors to modernize their activity. After running through the various different motivations and levers of social change, Marjorie Jouen shows how these tools could be transposed to subserve the modernization of public action, so as to improve its efficiency and develop instruments that would enable it concretely to meet its desired objectives.