EN
The article dwells on theoretical analysis of optimum investment trajectories in growth models in which the rate of population change varies. Two sets of assumptions were adopted to study the implications of abandoning the fixed rate of population increase condition. The first assumes that the rate is exogenous and does not depend on the level of wealth. The second assumes that population growth rate diminishes together with the increase of output per capita. Optimum investment trajectories for both assumptions were calculated and compared with the traditional results. Optimum investment policies, arrived at for non-malthusian models, markedly differ from the classical ones. The paths of those optimal trajectories depend on the way the population growth rate is introduced into the models (exogenously or endogenously).