Should couples combine finances? What a study tested

Somewhere around the second lease or the first wedding invite, the question comes up. Do we merge? Most advice on this is opinion. One study actually tested it.

The experiment

In a paper published in 2023 in the Journal of Consumer Research, researchers including Eli Finkel recruited engaged and newlywed couples and randomly assigned them to open a joint bank account, keep separate accounts, or make no change. They followed the couples for two years.1

The joint-account couples kept their relationship quality steadier. The other groups saw it decline over the same period. The authors connect this to couples’ goals lining up and to a more communal “our money” way of thinking.1

Because couples were randomly assigned, this is closer to cause and effect than most relationship research. Still, it covers engaged and newly married couples in one period. It doesn’t tell you what happens to dating couples, or people who’ve already been divorced.

Three setups people actually use

Financial therapist Amanda Clayman, quoted in Vox, describes the common options as one pot (everything shared), two pots (everything separate) and three pots (a joint account plus one each).4 NPR’s Life Kit calls the third one “theirs, mine and ours”.2

The FDIC adds the question of how shared costs get split: all income combined, each person covering certain bills, or by percentage, so someone earning 60% of the household’s income pays 60% of the shared costs.3

When separate makes sense

Financial therapist Lindsay Bryan-Podvin told NPR that if you’ve been through financial abuse, keeping money separate is reasonable. She also suggests separate accounts, or the three-pot setup, for people coming out of a divorce or separation.2 Vox lists financial abuse and financial infidelity among reasons to hold off as well.4

It’s also worth knowing what a joint account means legally. The FDIC notes that each co-owner can withdraw the full balance without the other.3 That’s convenient in an emergency and a risk if trust is shaky.

The conversation before the account

Talk early. Bryan-Podvin suggests having the money conversation before big shared steps like moving in or buying a car.2

Swap the “money baggage”. Megan Ford, who directs a center on couples and money at the University of Georgia, suggests talking about how your past shaped your money habits.4

Keep something that’s yours, not hidden. Ramit Sethi, quoted in Vox, recommends each partner keep an account the other can’t touch, but never a secret one.4

Question 50-50. Bryan-Podvin points out that equal splits can be unequal in practice, for instance when one person carries large student loans.2

Look at credit together. The FDIC suggests understanding each other’s credit reports before borrowing as a pair.3

If kids are part of the long-term plan too, bringing up kids while dating covers how to raise the other big future question without it feeling like an interview.

Limits worth keeping in mind

• The experiment covered engaged and newlywed couples, not people who are only dating.
• “Relationship quality” was self-reported. It doesn’t capture every way money affects a couple.
• None of this is financial advice for your situation. A planner or financial therapist can look at the specifics.