Single women are losing in today's economy

• Sometimes it feels as if everyone is pushing women to get married — even the US government.

• While more millennials are postponing or forgoing marriage, the economy hasn't caught up.

Kate Mannelly, a 29-year-old teacher living in Boston, wants to move into a one-bedroom apartment. But prices are nearly the same as the rent she now splits on a two-bedroom unit with her sister.

"I do feel like the renting industry really caters toward couples and those who are sharing one room and can split rent," she told Insider. "What does that mean for the rest of us that are not in a relationship or not splitting one bedroom with a partner?"

Mannelly is experiencing an effect of the single tax, in which singles are penalized in an economy shaped by post-World War II values of marriage and family. Since then, times have changed. Millennials are postponing homebuying, marriage, and childbearing until later — or never. An Institute for Family Studies analysis of US Census data found that a record 35% of US adults ages 25 to 50 had never married as of 2018. In 1970, that share sat at 9%.

It's a sign of both distress and progress: As millennials created a new version of the American dream, the single life has become more socially acceptable — and preferable for many. But while stigmas have shifted, the economic system that incentivizes marriage hasn't. The costs of being single show up in everything from social life to the tax code, housing, and health insurance.

While costs are higher for singles, they also tend to earn less on average than their partnered counterparts. Plus, women, who already earn less than men on average, are even further behind if they are Black or Hispanic. That disparity becomes even more problematic as millennials weather yet another economic woe: 40-year-high inflation.

Claudia Goldin, professor of economics at Harvard University, said that research highlights marriage as a clear cause of higher earnings for men, she said.

But for women, she said, "There is little about a positive causal effect of marriage or partnering."

One is the costliest number

The US government defines "single" as people who aren't married, meaning you can legally be single and still have a partner. Most commonly, it refers to those who aren't married, living with a partner, or in a committed relationship. That's how the Pew Research Center defines singles, which describes 31% of Americans in its 2020 report on America's singletons.

Many single people seek solo living. But, as Mannelly's case suggests, that's hard to do in many US cities where the median rent on a one-bedroom apartment is nearly the same price as a two-bedroom. The declining affordability due to today's housing crisis could also undo progress women have made toward homeownership.

"This might sound so depressing, but I truly cannot wrap my head around when I'll ever be able to buy a home," Mannelly said of living in Boston. "It just feels so unattainable right now. In some ways, I'm resigned to the possibility that I may have to rent forever if I choose to live here."

About 65% of single women reported that they would rather not wait until they were married to buy homes, according to data from Bank of America released last month. So far, one in three have bought, but Kathy Cummings, senior vice president of homeownership solutions at Bank of America, told Insider many single women don't feel financially ready to buy a home on their own even if they're emotionally ready.

Megan Rowsey, a 27-year-old single mother, took the leap in 2019 but told Insider she didn't think she'd be able to do the same in today's economy.

"I don't think I could buy a home in today's market, as I was only able to afford a fixer-upper," she said, adding that the renovations she's been making haven't been cheap or easy. "Prices on homes and materials have gone up like crazy, and I wouldn't have been able to make it livable even if I did get the house."

No one to split the bill with

In her book "Spinster: Making a Life of One's Own," the author and journalist Kate Bolick explores the appeal of choosing a single life for millions of American women. "Studies show that a woman who lives alone is more likely to have an active social life and maintain family bonds," she wrote, "not because she has extra time on her hands, but because these are the bonds that sustain her."

But maintaining this bigger social network can be expensive when you're doing it by yourself. It means fewer dinners at home alone and more drinks out with coworkers or dinners out with friends. There are Uber rides home and Hinge dates — it can all put a dent in the bank account.

So, too, can shelling out on gifts and travel to visit all these loved ones. Some travel businesses like hotels and cruise lines charge solo travelers a "single supplement," when only one person is using the services. It doesn't help that these activities are all more expensive now thanks to inflation.

This isn't to say that married couples don't have their own social lives to pay for, but couples can split the cost. Plus, many gym memberships, cellphone plans, and meal-delivery services offer deals for family plans.

Uncle Sam wants you to get married

Deals for couples and families are a ripple effect of a single tax endorsed by a government that favors the married.

The tax code, for example, used to call for Americans to file income taxes individually. In 1948, right around the birth of the post-war version of the American dream, joint filing was implemented to let married couples combine their incomes for tax purposes.

While couples that earn about the same income see little to no benefit from filing jointly, couples in which one partner earns all or most of the income benefit from a "marriage bonus" in which the higher earner's bracket can drop after marriage. Married couples also enjoy more tax breaks than single filers, such as a larger standard deduction.

Insider calculated the taxes for an American who earned $50,000 for the 2021 tax year using the Tax Policy Center's marriage calculator. With no itemized deductions, they would owe $4,314. If they married a partner who didn't work, earning no income, together they would only owe $2,629 in taxes because $50,000 falls into a lower tax bracket when married.

Healthcare, Social Security, and retirement accounts all follow suit. For some married couples, it can be cheaper to add a spouse onto their employer-sponsored health insurance than to have separate policies. Spouses can also receive up to 50% of their other half's Social Security benefit, depending on their earnings. IRA and Roth IRA income limits are also higher for married couples with one income.

That's not to mention the challenges women already face on these fronts, who have less money saved for retirement and spend about $15,000 more on healthcare than men during retirement, according to a 2019 Fidelity analysis.

One upside: Women tend to live longer than men. Actually, that's a financial downside as well, Whitney Pesek, director of childcare policy at the National Women's Law Center, previously told Insider.

"While women end up with less retirement income than men, they also tend to usually need more retirement savings because women tend to live longer than men," she said. "Women are more likely to be single later in life and have higher health costs than men as they age."

Until America's singletons get a stronger support system, single women will continue to face an uphill battle in affording the things they want.

"For a long time, and even still if I am being honest, I would think of all the things I could do with dual income," said Rowsey, the single mom and homeowner. "At some point though, I realized I was wasting time on an idea I was not guaranteed."