document: An American study of the prevalence of multiple partner fertility has found that 28 % of all US women with two or more children have children by more than one man . '' `` I was surprised at the prevalence , '' '' said demographer Cassandra Dorius , a postdoctoral fellow at the University of Michigan Institute for Social Research . '' `` Multiple partner fertility is an important part of contemporary American family life , and a key component to the net of disadvantage that many poor and uneducated women face every day , '' '' he said .
extractive_keyphrases: postdoctoral fellow dorius multiple partner fertility one man 28 two or more children family life research study component us women contemporary children disadvantage important poor women found american prevalence
abstractive_keyphrases: common paternity she found income white mothers analysed data all levels 22 more common among minority women gave birth hispanic mothers 4000 us women demographers different men common triangulated information examined man youth washington mothers 35 marriage annual meeting multiple partner fertility women younger women their childbearing years data included divorce national sample presented live 27 years urban areas kids assess prevalence said demographer cassandra dorius african 59 low income population association education child reports less education each household capturing single parenthood survey different fathers fertility common multiple individual men american study interviewed frequently tied nonresidential relationships not living with uneducated women face national analysed nonresidential previous surprisingly postdoctoral individual capturing social research multiple partner multiple annual longitudinal