This chapter reviews the way in which the economics and sociology of conventions (EC/SC) addresses the social and solidarity economy (SSE). This sector encompasses organizations that operate on principles of solidarity, equality, and nonprofit, among others. The chapter examines two pervasive notions in the SSE: the values espoused by SSE organizations and the political dimension of their activities. The aim is to highlight that it is values that underpin the actions of stakeholders in the SSE sector. In other words, individuals mobilize values to justify their decisions. However, given that SSE organizations (SSEOs) operate in sectors subject to both public regulation and market competition, these values are put to the test. The theoretical tools of the EC/SC enable values to be studied as shared representations of the “right” or “fair” way to produce things, evaluate individuals, or perform an activity and to analyze how those values fit into their institutional environment. The chapter demonstrates how the theoretical instruments of the EC/SC can be used to examine the political aspect of SSEOs. One approach is to analyze democratic bodies as spaces of power in which members have the capacity to determine what is valuable (to decide which activity should be performed, what the right way is to produce things, etc.). In this context, François Eymard-Duvernay’s concept of the power of valorization is employed. An alternative approach is to examine the capacity of SSEOs to alter representations and transform institutions.