This paper documents increasing cohabitation in the United States, and the
implications of this trend for the family lives of children. The stability
of marriage-like relationships (including marriage and cohabitation) has de
creased - despite a constant divorce rate. Children increasingly live in co
habiting families either as a result of being born to cohabiting parents or
of their mother's entry into a cohabiting union. The proportion of births
to unmarried women born into cohabiting families increased from 29 to 39 pe
r cent in the period 1980-84 to 1990-94, accounting for almost all of the i
ncrease in unmarried childbearing. As a consequence, about two-fifths of al
l children spend some time in a cohabiting family, and the greater instabil
ity of families begun by cohabitation means that children are also more lik
ely to experience family disruption. Estimates from multi-state life tables
indicate the extent to which the family lives of children are spent increa
singly in cohabiting families and decreasingly in married families.