Multiple Partner Fertility across Two Cohorts of Women in the United States

Sara R. Zobl, University of Michigan
Pamela J. Smock, University of Michigan

Family demographers have been paying increasing attention to the phenomenon of “multiple-partner fertility” (MPF). This refers to having biological children with more than one partner. Yet to date we know little about trends in multiple partner fertility or about the shifting sources of the phenomenon. This paper aims to fill that gap. We document: (1) trends over time in the incidence of multiple partner fertility; and (2) the changing sources of multiple partner fertility. By the latter, we uncover the changing share due to non-union fertility, childbearing in cohabiting relationships, and childbearing in (re)marriages. We draw on two cycles of the National Survey of Family Growth, and use an indirect method to uniquely identify fathers for women not in coresidential unions, to fulfill these aims.