Fertility in Married and Cohabiting Unions: A European Comparison

Roberta Rutigliano, Universitat Pompeu Fabra
Gosta Esping-Andersen, Universitat Pompeu Fabra
Mathew J. Creighton, Universitat Pompeu Fabra

Although union formation and fertility are intimately related, it is far from clear how they influence each other. In this study we analyze how fertility behavior is related to different union types, focusing on married versus cohabiting partners. Using a multi-process model, we estimate two equations simultaneously: fertility transitions and selection into different union types (i.e. the competing risk of marriage versus cohabitation). Our analysis focuses on first and second births, utilizing GGS data for Norway and FFS data for Spain. For both countries, the results confirm the widespread expectation that birth transitions are more prevalent within marriage. This is primarily the case for second births. The advantage of this approach is that it provides a measure of the correlation between the different processes. For Norway we find a significant association between selection into partnership and fertility; surprisingly, this appears not to be the case in Spain.