Apparently monogamy makes dollars as well as sense.

Moving In Together Doesn’t Match the Financial Benefits of Marriage, but Why? 

Married couples are four times as wealthy as unmarried couples who live together 

By Julia Carpenter 

A walk down the aisle can be a route to greater wealth and prosperity for couples in the U.S. Married people have higher net worths and are more likely to be homeowners than their unmarried counterparts their age are.  

The mystery, though, is why cohabitating but unmarried couples struggle to build wealth in the same way. As of 2019, the median net worth for cohabiting couples age 25 to 34 was $17,372, a quarter that of the $68,210 for married couples of that same age range, according to data from the Federal Reserve Bank of St. Louis. For singles it is $7,341.

“If you build an arch, the cornerstone is the first piece you put in and the capstone is the last,” he said. “What this means is people see an economic bar they need to clear before they get married. Couples wait until they have good jobs, a car that won’t break down, maybe even a house. Then, they get married.”

Melissa Mowery, a 30-year-old communications manager in Asheville, N.C., has been with her boyfriend for five years and living together for nearly four. The two don’t share a joint bank account, but they split the cost of rent and other bills. Even so, Ms. Mowery said she can’t make sense of the financial gap between her relationship and that of married couples. 

“We’re already saving a lot of money and splitting the cost on most things,” she said. “I don’t understand how married couples are accumulating wealth in a way we’re not doing.” 

While there are legal and tax benefits to marriage, research suggests the financial security and long-term mind-set of those who tie the knot may also be a powerful driver of wealth. More married couples pool their money—such as sharing savings accounts and investing together—to achieve certain goals, Ms. Kent said. Cohabiting couples are less likely to combine finances and investments.

Working with two incomes and combining their investments to maximize compound interest can significantly increase a couple’s financial prospects, said Emily Garbinsky, associate professor of marketing at Cornell University, who has studied couples’ financial behavior. Simply put, married people may be more likely to be on the same page financially, she said. 

“Married people may be much more likely to have these conversations around what goals they have for their financial future,” she said. “There seems to be something very special and unique about deciding to share finances.” 

Unmarried couples may be less willing to commingle their money, said Prof. Garbinsky.

“Our money, our income, represents a huge part of who we are,” she said. “[Sharing] that can be scary for people, so they tend to be very protective.”  

Both married and unmarried couples who do pool finances also experience greater relationship satisfaction and may even stay together for longer, Prof. Garbinsky said. 

Housing is one of the biggest factors in establishing a couple’s wealth. Compared with single people and cohabiting couples, married couples hold a larger concentration of housing wealth, according to data from the St. Louis Fed. 

“Most of my married friends have bought a house,” Ms. Mowery said, noting high housing costs in her area. “I just don’t know how they did it. Everyone talks about how when you get married, you accumulate wealth but I don’t know what that means.” 

In the current hypercompetitive housing market, as smaller, more affordable starter homes vanish and housing affordability declines, single people and cohabiting couples are often at a disadvantage.