The aim of this paper is to analyze gender differences in the determinants of the gap between actual and desired fertility in Spain. To this aim, we exploit the 2018 Fertility Survey (EF2018) from the Spanish Statistical Institute (INE). A binary probit model shows that gender differences in the risk (and its pattern) of not reaching the desired family size are generally more pronounced amongst parents than amongst childless adults. For women, a high level of education, a potentially unstable employment situation (as an employee in the private sector) and not living with a partner increases the risk of not having the desired number of children. For men, variables related to income instability or low monthly income cause a more pronounced differential between desired and actual parenthood than amongst women, while neither educational level nor partner status – amongst those who are already fathers – significantly influences their probability of not reaching the desired number of children.
