The author contends that aspects of the world economic crisis and the fertility decline in developed countries have origins in the disequilibrium in the age distribution of the population, caused by World War II and exacerbated by the rigidity of the employment structure. Theories linking the age structures of populations, global equilibrium in supply and demand, and capital accumulation are outlined. The impact of employment conditions on fluctuations in fertility as hypothesized by Easterlin is considered, and a regression model is applied to data for European and North American countries.