The organization of uncertain markets.

Summary This thesis aims to highlight the processes by which markets are organized in which uncertainty reaches very high levels and the very nature of the good exchanged is problematic. These markets, described as "uncertain", would mark the exhaustion of a Fordist ideal of labor exchange, now replaced by brief, ephemeral relationships with multiple employers. This hypothesis is examined through the study of the case of freelance journalists and intermittent actors. The analysis of the drama and freelance markets mobilizes the tools of economic sociology and highlights the relevance of exchange relations in the description of these markets. First of all, they reflect their structure. The examples of the social construction of these relations thus show, in their divergences, the way in which these markets are organized around segmentation phenomena. The degree of confusion about the nature of the goods exchanged, whether products or labor, as well as the positioning of firms in this system of markets, contribute to defining the temporalities in which these employment links are inscribed. These then inform these markets. In particular, several regimes of relationships coexist in uncertain markets, and the engagement of individuals in a durable exchange relationship profoundly modifies the competitive constraints that are exerted on them and introduces predictability and organization into individual activity. The existence of this second regime of relations also questions the market structures themselves: they blur the boundary between market and organization, and complicate the segmentation of these markets.