Fertility in Denmark has fallen despite educational attainment increasing and educational attainment being positively correlated with fertility. In a descriptive decomposition, lower partnership formation accounts for about as much of the decline as lower fertility within couples, while the shift toward higher education partly offsets it. We develop and estimate an equilibrium model of education, marriage, labor supply, and fertility with imperfectly transferable utility and unobserved heterogeneity in women’s fertility preferences. We identify women’s and men’s preferences for children separately from couples’ joint choices using variation in local marriage market conditions that shifts bargaining power. The estimates attribute the decline mainly to falling preferences for children among women, while men’s preferences change little. In policy counterfactuals, free childcare raises fertility by 3.4 percent, and partnership formation accounts for 41 percent of that gain. Joint taxation weakens incentives to acquire education and marry, producing a fertility decline more than three times its fixed-couple effect. Closing the gender wage gap lowers fertility 2.8 times as much in full equilibrium as in the fixed-couple benchmark, partly by shifting bargaining power toward wives.

We study marital sorting using a novel dataset from a marriage matching platform, which uniquely records a rich set of pre-marital attributes, including preferences for children and for the division of housework and childcare. Unlike census or post-marital surveys, all characteristics are collected prior to matching and validated using official documents, yielding clean measures of preferences uncontaminated by post-marital coordination. Applying a multidimensional matching framework to twelve attributes, we find strong positive assortative matching across all dimensions. Age is the most salient trait, but preferences for children are the second most important—exceeding education—a pattern largely invisible in standard data. Preference measures play a distinct role in the matching process: they exhibit limited cross-attribute interactions with sociodemographic and anthropometric characteristics, in contrast to the pervasive interactions among those attributes. A low-dimensional factor representation shows that preferences for children constitute a separate and salient margin of sorting. Using the staged structure of the platform, we further show that assortative matching along different dimensions emerges at distinct points in the dating process: sorting by age and income is already present at the initial Application stage, whereas sorting by preferences for children becomes robust only at later stages of relationship formation, reflecting selective continuation rather than sorting at the point of final agreement. A simple theoretical exercise demonstrates that ignoring preference-based sorting and assuming homogeneous preferences across couples leads to biased estimates of policy effects on subsequent household decisions.

We examine how working from home (WFH) affects men’s participation in childcare and housework and their attitudes toward family. Because WFH is an endogenous decision, we apply a first-difference instrumental variable estimator, taking the degree to which one can work from home, measured at the individual level, as the instrument. We find that WFH increases the time that men spend on household chores and with family, and the fraction of men who consider life more important than work. Although WFH decreases their commuting time, we find no evidence that it reduces working hours or self-perceived productivity.