The aim of this paper is to show that a robust determination of unemployment equilibria can be based on the integration of credit rationing into a general equilibrium model. We first review some of the Keynesian macroeconomic models. We show that the problems bequeathed by Keynes' legacy are only partially solved by the strand of the new Keynesian economics based on market imperfections and endogenous rigidities. In order to overcome these problems we refer to credit rationing. In particular, we build a simple general equilibrium model in which prices are-in principle-perfectly flexible and credit rationing implies unemployment equilibria