Reciprocal behaviour in partnership and fertility: new mechanisms for family formation in Europe and the United States

Across Europe and the United States, an increasing proportion of births are to unmarried women. That said, many cohabiting relationships are translated to marriage after birth- even in settings where cohabitation is common, such as Norway. Most existing analyses either assume a one-way transition (i.e. marriage to birth), or that these processes are correlated. This analysis argues that in settings where birth triggers marriage, such a causal association cannot be captured by existing approaches. I employ a cross-lagged bivariate regression to model the two processes of union formation and birth incidence, to establish whether such a causal relationship exists, and how it varies across national contexts. Data for this analysis come from the Harmonized Histories, a comparable dataset encompassing the United and 15 countries in Europe, which include retrospective data on both partnership and fertility. Preliminary results indicate that in Norway, birth is indeed a trigger for marriage. In Italy, however, there is no significant effect of birth on union status; consistent with a traditional union formation pattern. In Bulgaria, while there is an initial effect of birth inducing marriage, this effect diminishes- indicating that birth will not trigger a transition to marriage in established cohabiting unions.