URL des Documents de travail : http://ces.univ-paris1.fr/cesdp/cesdp2011.htmlDocuments de travail du Centre d'Economie de la Sorbonne 2011.05 - ISSN : 1955-611XDiscrimination models have diffivulties to study discrimination without assuming that prejudiced firms are more productive and results lead to workers' segregation. In this article, the model uses oligopsony and heterogeneity of workers' preferences to obtain a persistent discrimination. Firms hire both thpes of workers and pay a lower wage to the workers discriminated against whatever their taste for discrimination. A single prejudiced firm leads to a substancial wage gap in all firms. Consequently, the existence of discrimination allows a non-zero profit for unprejudiced firms and ...