When applied to long-run dynamic models of economic development in free capitalist economies, the conceptualisation of the rate of profits will set the type of distribution mechanism that rules in such models and will thereby affect both the variables selected for inclusion and the method of analysis of those variables in the theoretical construction. In questions of growth the economist must not only be concerned with various methods of attaining an increase in whatever output aggregate is chosen, but he must also pay sufficient attention to who receives the benefit of this increased production, and finally whether this division is conducive to the stability of the model as formulated.