In the field applied to labor and employment issues, a significant part of the literature based on the economics and sociology of conventions (in short EC/SC) approach focuses on the analysis of the matching dynamics between labor supplies and demands and of the incidences of recruitment practices on labor market segmentation and unemployment. The chapter first describes the critical contribution of François Eymard-Duvernay and his fruitful hypothesis about the labor quality convention and the power of valuation of the firms, as well as other contributions conducted in the Centre d’études de l’emploi [Employment Research Centre] in France. The following sections develop two pillars of the approaches developed in EC/SC: the importance, in job channel information and selection criteria on the format in which information is conveyed and the diffusion in the labor market of the labor quality conventions of the employers. This chapter also discusses the meanings and implications for the labor market segmentation and public employment policies of EC/SC approaches.