Statistically the number of marriages that fail when the couples live together prior to marriage
Executive summary
A consistent body of recent research finds that premarital cohabitation is associated with a higher risk of marital dissolution, but the size of that risk depends heavily on timing (moving in before versus after engagement), number of prior cohabiting partners, and the study and controls used; broadly, recent U.S. estimates show divorce rates around 25% for couples who lived together before marriage versus about 20% for those who did not, with larger gaps when cohabitation began before engagement [1] [2].
1. The headline numbers: modest absolute differences, notable relative risks
One of the clearest recent summaries reports that 25% of couples who cohabited before marrying in 2010–2019 ultimately divorced compared with 20% of couples who did not cohabit before marriage, an absolute difference of 5 percentage points and a relative increase of about 25% [1]; the Institute for Family Studies frames the larger “cohabitation effect” around contemporary figures showing roughly 70% of couples live together before marriage [2].
2. Timing matters: before engagement is where risk concentrates
Multiple analyses find the risk is concentrated among couples who moved in together before they were engaged: Stanley and Rhoades report that marriages of those who cohabited before engagement were substantially more likely to end than marriages of those who only cohabited after engagement or not at all, with reported divorce rates of roughly 34% for couples who moved in before engagement versus about 23% for those who cohabited after engagement in some summaries—an effect the authors link to “sliding” into commitment and an inertia-driven increased chance of ending in divorce [2] [3].
3. Mechanisms and heterogeneity: selection, inertia, and serial cohabitation
Researchers debate whether the association is selection-based (different kinds of people choose to cohabit) or causal (cohabitation changes attitudes and commitment); Stanley and colleagues argue for both, pointing to “inertia” — the idea that shared constraints make it harder to leave suboptimal matches — and to the finding that serial cohabitation (living with multiple partners before marriage) raises divorce risk further, sometimes by roughly 60% relative to those who did not cohabit before marriage [4] [1].
4. Counterevidence and caveats: not a universal condemnation of cohabitation
Not all studies agree that cohabitation raises divorce risk once all factors are controlled: at least one analysis (summarized in a fact-checking piece) found no overall negative effect for engaged couples who cohabited versus those who did not, and national surveys show large majorities, especially among younger adults, who believe cohabitation helps test compatibility [5] [6]. Moreover, observers note that while some reports highlight 34% divorce among those who cohabit before marriage, that still means two‑thirds of such couples remain together [7].
5. Bottom line for the numbers: range, context, and what the statistics do — and don’t — prove
Statistically, the best-supported contemporary range is that about one in four marriages ends in divorce for couples who lived together prior to marriage versus roughly one in five for those who did not (25% vs 20%) and that the gap widens when cohabitation predates engagement (estimates like 34% vs 23% have been reported), but these are associations not ironclad causal claims and vary by sample, controls, and how “cohabitation” is defined [1] [3] [2] [4]. The research consistently flags heterogeneity — timing, number of prior partners, socioeconomic context and values — as crucial moderators, and also documents that cohabitation is now the norm for the majority of couples [2] [4].