Couples Who Combine Finances Are Happier. So Why Don’t More Do It?

Married couples hold four times as much wealth as unmarried couples who live together, and researchers point to combining finances as one reason why. 

So why don’t more couples join finances?

By one measure, 43% of couples said they have only joint bank accounts, according to a 2022 survey from CreditCards.com. Thirty-four percent of couples in the same poll have a mix of joint and separate accounts, and 23% keep their finances entirely separate.

The choice often comes down to how people evaluate the risks and the rewards. Should a couple break up or divorce, joint finances can be harder to disentangle, and one person’s hard-won money might be lost in the ensuing dissolution of what is considered “yours” versus “theirs.”

There are some advantages to merging accounts, according to research from

Emily Garbinsky,

associate professor of marketing and behavioral scientist at Cornell University, and

Joe Gladstone,

an assistant professor of marketing who studies consumer decisions at the University of Colorado at Boulder. Their research shows couples who share money also boast greater relationship satisfaction. In addition to the benefits of having access to a larger pool of assets, combining finances leads to a greater feeling of accountability, since each half of the couple can observe the other’s spending and saving habits more closely, they found.

In many studies, Prof. Garbinsky and Prof. Gladstone looked at how individual partners’ money decisions changed depending on whether they were spending from their separate or joint accounts shared with a partner. They found that those spending from a joint account were less likely to make “hedonic” purchases and instead fell back on more “utilitarian” options. In one study, for example, participants spending from a joint account more often chose to buy a coffee mug—perceived as a more sensible purchase—over a beer tankard, which was seen as the less reasonable option.

The research demonstrated that greater accountability doesn’t mean greater conflict, Prof. Gladstone said. “Maybe in some ways, the more that we can increase that transparency and awareness of each other’s behavior, that might keep everyone more coordinated and on track,” he said.

Not every couple is ready to take the financial plunge.

Nathan Gallagher,

a 30-year-old waiter and bartender living in Brooklyn, doesn’t yet share a bank account with his live-in partner. But every month, the two sit down to talk about their respective accounts, shared expenses and the financial progress they are making together as a couple. They split rent and other household bills, and if one of them needs funds during a lean time, the other partner doesn’t hesitate to step in and help with the cost, Mr. Gallagher said.

“We’re really fine with sort of taking things at our own pace, but combining finances, I can see being a step in the future that we take,” he said.

To

Jesse Cramer,

relationship manager at Cobblestone Capital Advisors in Rochester, N.Y., Mr. Gallagher’s approach speaks to the range of ways younger couples choose to combine finances.

“On one end, you have finances that are so separate that it’s like two strangers, from a financial point of view, and when one of them picks up dinner, the other Venmos them for half,” Mr. Cramer said. And on the opposite end are couples who share everything. 

There is also a middle road to take, and Mr. Cramer says that has been his approach. While he has plans to one day join finances with his wife, to whom he just got married in September, they have yet to open a joint account. Still, the two have already had important conversations about shared financial goals. They agree to discuss when they will share costs and when keeping purchases separate makes sense.

When it comes to sharing money with a partner, Mr. Gallagher said he is of the opinion that doing so really depends on an individual’s personal goals and their own risk tolerance. Weighing what you gain versus what you lose is a very personal calculation, he said.

“A lot of people have money trauma they bring into relationships,” he said. “How money and relationships interact is based on people’s personal history with money.”

But the benefit of combining finances might outweigh those risks, especially for those with less wealth, Prof. Gladstone said.

“If you have lower income and then pool together, it might feel like a lot more money, whereas if you have two really affluent people and you pool together, you’re still super rich,” Prof. Garbinsky said.

Write to Julia Carpenter at julia.carpenter@wsj.com