This study examines the risk of separation over relationship duration – including the first non-residential episode – and compares the effect of family formation to the stabilizing effects of household and marriage formation.

Little is known about the variation of relationship stability with household, marriage and family formation when the length of the relationship is measured from its very start. Literature shows that children positively affect the stability of cohabiting and married couples at least in their pre-school years. These studies however neglect that household and marriage formation are often synchronized with first childbearing and thus, the positive effect of first children may be partly attributed to a ‘honeymoon’ effect after household or marriage formation. Furthermore, a pregnancy can have little or even a negative effect on the stability of a non-residential partnership, an aspect that literature has not addressed so far. In sum, the effect of children on overall relationship stability remains still to be evaluated. This study treats cohabitation and marriage as episodes of the same relationship and disentangles the relative effects of household, marriage and family formation on the risk of separation.

We use fertility and partnership histories of women born 1971-1973 and 1981-1983 gathered in the German Family Panel (pairfam) and control for their observed and unobserved characteristics in a piecewise continuous hazard model. The empirical findings reveal that family formation stabilize relationships, but to a lesser extent than other relationship events like household formation and marriage. A closer look on marital status suggests that childbearing increases stability among non-marital relationships, while it does not lead to much further stability increases among marriages.