Capital Accumulation, Inertia of Consumption and Norms of Reproduction.

A model of capital accumulation is built in relation with fertility and consumption. Avoiding to impose a direct analytical relationship between these three variables, the author studies the set of possible evolutions under the constraints imposed by the inertia of habit change. The conflict between the necessity to avoid impoverishment, the desire to increase consumption when possible and the reproduction intensity delineate the set of viable solutions and the set of attitudes leading to capital extinction. This qualitative view of change of behaviors provides an alternative explanation to historical fertility fluctuations outside the usual Easterlin framework.