Background: The decision about whether to start a family within a partnership can be viewed as a result of an interaction process. The influence of each of the partners in a couple differs depending on their individual preferences and intentions towards having children. Both of the partners additionally influence each other’s fertility intentions and preferences.

Objective: We specify, estimate, and test a model that examines the decision about whether to have a child as a choice that is made jointly by the two partners. The transition to the birth of a (further) child is investigated with the explicit consideration of both the female partner and the male partner in the partnership context.

Methods: An approach for modelling the interactive influences of the two actors in the decision-making process was proposed. A trivariate distribution consisting of both the female and the male partners’ fertility intentions, as well as the joint generative decision, was modelled. A multivariate non-linear probit model was chosen and the problem of identification in estimating the relative effects of the actors was resolved. These parameters were used to assess the relative importance of each of the partners’ intentions in the decision. We carried out the analysis with MPLUS. Data from the panel of intimate relationships and family dynamics (pairfam) was used to estimate the model.

Results: The biographical context of each of the partners in relation to their own as well as to their partner’s fertility intentions was found to be of considerable importance. Of the significant individual and partner effects, the male partner was shown to have the greater influence. But the female partner was found to have stronger parameters overall and she ultimately has a veto power in the couple’s final decision.