Cohabitation

Cohabitation is two people in a romantic relationship living together without being married. It is now the majority path into marriage across most of Europe and North America, and for many couples it is not a path into anything — it is the arrangement itself.

It is also the step on the relationship escalator that gets the least deliberation relative to how much it changes. Exclusivity gets a conversation. Marriage gets a proposal. Moving in often gets a lease renewal date.

For decades the finding was consistent and counterintuitive: couples who lived together before marriage divorced at higher rates than those who did not. It was repeated widely, usually without the caveats.

That finding has substantially weakened and in recent cohorts largely disappeared. The reason is selection. When cohabitation was uncommon, the people doing it differed systematically from those who did not — less religious, less traditional, more accepting of divorce. As it became the norm, the selection effect thinned out and so did the association.

What survived is more specific and more useful. Age at moving in predicts outcomes better than cohabitation itself. Arielle Kuperberg's work found that once you control for how old people were when they started living together, the premarital cohabitation effect largely vanishes — moving in at 20 predicts trouble, moving in at 28 does not, whether or not there was a wedding in between.

Rosenfeld and Roesler add a wrinkle worth knowing: cohabitation is associated with slightly lower divorce in the first year of marriage and slightly higher over the longer run. Living together first appears to smooth the transition and to defer, rather than prevent, some separations.

The most useful concept in this literature, from Scott Stanley and colleagues.

Some couples decide to live together: they talk about what it means, what they are committing to, and what happens if it does not work. Others slide into it — one lease ends, someone is staying over four nights a week anyway, and the boxes move.

Sliding matters because of inertia. Living together raises the cost of leaving — shared lease, shared furniture, shared routines, shared friends — and it raises that cost for both people whether or not either had decided the relationship was worth it. A couple who would have separated at month eight can find themselves at month thirty, still together, because leaving became expensive before either of them decided to stay.

That is the finding to act on. It says nothing about whether to live together and quite a lot about how: the difference between sliding and deciding is one explicit conversation, and it is not a conversation about furniture.

Common-law marriage mostly does not exist. Only a handful of US states still recognise it, and England and Wales do not — the "common-law wife" is a persistent myth with no legal content. A couple who lived together for twenty years may have almost none of the protections a couple married for two years has.

What that means in practice, and what cohabiting couples routinely discover at the worst time:

• Property stays with whoever's name is on it, regardless of who paid what
• No automatic inheritance without a will, and in some jurisdictions no standing to contest
• No automatic next-of-kin status for medical decisions
• Nothing equivalent to spousal maintenance on separation

Cohabitation agreements, wills and powers of attorney close most of these gaps and are far less work than assembling them retroactively. This is general information rather than legal advice, and the position varies sharply by jurisdiction.

If the research points at one thing, it is that the difference between sliding and deciding is made of specific questions rather than good intentions.

What is this — a step toward something, or the arrangement itself? What happens to the flat if we separate? Whose name is on what, and does that reflect what we both think is fair? What are we each assuming becomes shared, and what stays separate? And how will we know if this is not working, given that it will be harder to leave once it starts?

Those are boundary questions more than logistics, which is why couples who have not settled their boundaries find moving in surfaces every one of them at once.