This paper aims at a critical and constructive assessment of some extensions of Keynes’s analysis of effective demand to the long period and growth. A criticism is addressed to a single-cause interpretation of the demand-led growth models and to the notion of normal capacity utilization adopted in such models. A positive argument tries to find a distinctive characterization of those extensions in the productive and financial conditions that make effective the autonomous changes in aggregate demand. It suggests a notion of normal capacity utilization as a range of distributions of normal utilization, related to the cost minimizing choice of techniques and to the persistence of the long term expectations of normal prices underlying the investment decisions. In such a context a long-period analysis with normal prices should avoid a dual steady growth where constant relative prices of capital goods correspond to constant proportions among their total stocks.