Les relations entre l'investissement et la population

[eng] SUMMARY Population theory which was such au important ingredient of classical economics receives too little attention in current theory This is surprising since the volume of investment requirements receives great attention ami population increase is the most iir.portant element in these requirements By tlie use of fundamental dynam equation set out in arfU Dynamic Economics and elsewhere an attempt ia made to show tlie part played hy population increase in the dynamic equilibrium In the case of mature economies the population increase should make stagnation and recurrent recession less likely for two reasons First it raises the natu ral or maximum convenient rate of increase of output and thus makes it more likely that the economy can sustain warranted rate of increase without frequently going into downward spiral tilis warranted rate being that determined by Keynesian analysis as that which is barely sufficient to maintain progress under the profit incentive Secondly the increase in population tends to depress the warranted rate and thus contributes in this way also tovards making recurrent recessions less likely It is notable that the American stagnation of the thirties was accom panied by large fall in the rate of increase of population there and by sizeable fall in the rate of increase of working population Those who fear serious American recession in future may be encouraged by the fact th;it the prospective population increase will be considerably higher and more conducive to sustaining high employment