Marriage shapes how couples allocate work, accumulate assets, and insure against risk. Family law provides default rules that redistribute economic risk between spouses, promoting economic security and gender equality. Yet an increasing share of this redistribution is governed by private contract: the use of marital agreements — which allow couples to opt out of default property regimes — has grown across advanced economies. Despite their growing relevance, marital agreements remain largely absent from empirical research.

This paper fills this gap using a unique administrative database that covers the universe of marital agreements registered in Sweden since 1970 and is linked to population-wide registers. We document the prevalence and evolution of marital agreements over time, analyze selection into contracting, and examine the factors that drive couples’ choices of property regime. We further explore whether observed patterns are consistent with motivations such as asset protection, specialization, or precaution against divorce risk. By making marital agreements observable at the population scale for the first time, this paper establishes essential descriptive foundations for assessing whether default marital property rules effectively serve those they are designed to protect.

How do property rights within marriage shape gender inequality between spouses? This paper examines how marital property regimes affect within-couple gaps in labor market outcomes, wealth, fertility, and relationship stability, focusing on how asset integration shapes the distribution of economic costs and gains from marriage.

We exploit regional variation in default property regimes within Spain: while most regions apply the community of property, Catalonia and the Balearic Islands default to separation of property — an institutional difference that generates variation in intra-marital insurance and financial autonomy. Using rich Spanish administrative register data covering 2016–2022, we trace how within-couple gaps in earnings, employment, savings, and wealth evolve around marriage and divorce. An event-study difference-in-differences design allows us to decompose the extent to which the within-couple gender gap is shaped by the property regime. We further examine heterogeneity by assortative mating and pre-marriage earnings gaps, and use cohabiting couples — who face uniform property rules across regions — as a placebo group.

Using a unique dataset of all marital agreements in Sweden for more than sixty years, we study how private contracting shapes within-couple gender inequality, tracing its consequences for individual economic outcomes — including income, assets, and labour supply — both during marriage and at divorce. By making the property regime inside the household empirically observable, we assess the extent to which private contracting reproduces or reinforces socio-economic gender gaps.

We study how firm ownership intersects with marital contracting, asking whether men and women who own businesses differ systematically in whether and how they protect those assets through marital agreements. We also exploit policy reforms that shifted incentives away from salary withdrawal toward retained firm ownership, using this variation to identify how changes in the value of firm assets affect contracting behaviour.

We examine how the prospect of inheriting family wealth shapes both the decision to write a marital agreement and its content, highlighting how couples use private contracting to protect assets intended to remain within a family line.