Reconsidering previous exchanges between the économie des conventions (EC) and historical research, the article puts right different prejudices against EC and shows grounds for going deeper into cooperation. The first part is dedicated to the genesis and dynamics of conventions, in an open perspective on the ways value is placed on forms coordinating with others, the environment and oneself. Rather than looking for abstracts values, the article suggests to find the basis for repertoires of evaluation in empowering dependencies between human beings and their environment. This approach is favorable to a dialogue with historians on the domain of work identity, occupations and products or services. The second part deals with the politics of convention in a long-term perspective on power, authority and protest. Considering powers issuing from coordinative forms, it is claimed that this view helps to situate in a comparative and historical perspective nation-states among a variety of authorities which govern – possibly transnationally – through reduced conventions.