URL des Documents de travail : http://ces.univ-paris1.fr/cesdp/CESFramDP2009.htmDocuments de travail du Centre d'Economie de la Sorbonne 2009.76 - ISSN : 1955-611XIn an economy with a non-convex production sector, we provide an assumption on each individual producer, which implies that the survival assumption holds true at the aggregate level for general pricing rules. For the marginal pricing rule, we derive this assumption from the bounded marginal productivity of inputs. We apply this approach to intertemporal economies and we show how our assumption fits well with the time structure leading to a tractable existence result of equilibria, which could be apply to discrete dynamical growth models.Dans une économie avec un secteur de product...