Changes in the age distribution of parents, 1940-1980

There have been substantial changes in the fertility patterns of women in the past half century. Using data drawn from the 1940 through 1980 Public Use Samples of the U.S. Census of Population, we examine how these changes have affected the age distribution of parents for successive cohorts of children. We find that the average age of mothers and fathers has declined across cohorts of children. Part of the reason for this decline in mean ages is the precipitous decline in the proportion of black and white children who have mothers and fathers more than 35 years older than themselves. The proportion of white children born to teenage mothers changed very little during this time period. However, the likelihood of black children being born to very young mothers increased rapidly after 1960.