The period around 1960 marked a turning point in many aspects of American experience. A precipitous decline in fertility rates began. There was also a marked shift in female labor force participation characterized by a more rapid increase of young women's rates and a slowdown for older. On the social scene, there was an acceleration in divorce, a rise in suicide rates among the young, and an upturn in crime rates. In the political arena, there was growing alienation from the established system.

These developments contrast sharply with those during most of the previous two decades. After World War II there was a large and protracted baby boom. Labor force participation among older women rose at an unprecedented pace, whereas younger women's rates were flat. The historical uptrend in divorce slowed markedly, and suicide, crime, and political alienation were either constant or slightly declining.

I think these seemingly disparate developments were in part (and I stress in part) the result of a new relationship between population and the economy that emerged after 1940. This relationship centered on shifts in the size of the younger relative to the older working age population that produced pronounced reversals in the relative economic condition of the two groups. In this chapter, I take up first the factors responsible for the new pattern after 1940 and then the manner in which twists in age structure produced such startling shifts in socioeconomic conditions.