Beyond an economic determinism associating industrial structures (or “Fordism”) to collective bargaining, economics and sociology of conventions (EC/SC) envisages industrial relations (IR) from the concrete coordination of employees starting at the workplace level, as a normative expression of their collectivities. It has analyzed first IR as “investments in form” that can be used as reference enabling people to find their way in conventions of labor. IR are not the result of a pure spontaneous mobilization of the workers’ collectivity, but their dynamic is based on legal definitions of the collective agreements, the procedure of negotiation and their actors (employees-employers), by which it refers to legislation as a state production expressing conventions of the state. The sociohistorical emergence of labor law and employment explains a radical modernization of IR evidenced by the French case at the beginning of the twentieth century. IR have followed paths specific to different states influencing each other in a “histoire croisée,” leading sometimes to transnational negotiated legislations as in the 1990s’ European Union. The current developments of IR during the neoliberal period witness defensive dynamics, such as the mobilizations on employment in the face of intense restructuring, and offensive ones, as in the organizing of IT workers.