Many economists (Atkinson, 1995, Ferry 1995) have presented the mechanism of l'Allocation universelle as the new way forward by the modern social protection. In this article, we propose first to recall the context in which takes up the debate on “l'Allocation universelle”. Using a matching model in which horizontal differentiation of firms and workers is represented by a circle à la Salop (1979), we show that the introduction of “l'Allocation universelle” don't affect the equilibrium labor market.