This paper examines Steindls original 1952 model and relates it to subsequent stagnationist models. The model is then extended by introducing endogenous changes in the markup and a reformulation of the investment function. These extensions address weaknesses of the simpler models, find support in Steindls writing and leave intact some of Steindls key results. In a further extension, we add a labour market and analyse the stabilizing influence of a Marxian reserve-army mechanism. The implications of this model for the effects of increased monopolization are largely in line with Steindls predictions.
Steindl accumulation stagnation markup monopolization reserve army of labour