This paper examines the dynamics of Keynesian models that incorporate feedback effects from the labor market to income distribution, investment, aggregate demand and output. A baseline version of the model can generate endogenous growth cycles, but cumulative divergence and economic collapse also become possible for plausible parameter values. Ex-tensions of the model that include monetary and fiscal policy show greater robustness: the local instability of the stationary point leads to limit cycles (rather than complete collapse), even when large, destabilizing changes are made to parameters describing the private sec-tor. The robustness of the general approach is reinforced by the endogeneity of the fiscal and monetary policy rules. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )