Components of Change in the Number of Female Family Heads Aged 15-44: United States, 1940-1970.

Consideration of the statuses through which a woman passes en route to becoming a female family head suggested four components behind the 1940-1970 increase of 1,749,000 mothers aged 15-44 heading a family with a child. Changes in the probability that a mother at risk will form a separate family, rather than living as the child or other relative of a family head, is one component. Population growth, changes in fertility patterns and marital stability are the remaining three components. When applied to ever-married and never-married women it was found that about 36 per cent of the total increase in the number of female family heads was due to the increasing propensity of women at risk of headship to form separate families. A growing population of women aged 15-44, net of other factors, accounted for 17 percent of the increase: population growth in combination with the propensity component explained 68 per cent of the total increase in numbers of female family heads. The decline of childlessness among the married and rising illegitimacy among the never-married was related to about 13 per cent of the total increase, net of other components: in combination with the first two factors these three components explain about 90 per cent of the increase. Declining marital stability, independent of other components, accounts for only 3 per cent of the total increase. There is little difference in the relative importance of components between white and nonwhite populations [ABSTRACT FROM AUTHOR]