Women who retire when their husbands do may be giving up more wealth than they realize.
Married women overall are still in their peak earning years in their 50s and early 60s, while married men's earnings are on the decline, said economist Nicole Maestas, an associate professor of health care policy at Harvard Medical School and the author of a recent study about couples' income and retirement patterns.
As a result, married women typically sacrifice more Social Security wealth than married men when they retire early, said Maestas, who analyzed the University of Michigan's Health and Retirement Survey of more than 20,000 people 50 and older.
Social Security benefits are based on a person's 35 highest-earning years, so each additional year an older married woman works could replace an earlier year when her income was lower or she took time out of the workforce -- for instance, to raise children. Because older married men are typically past their peak earning years, the same is not true for them, Maestas found.
But women do typically retire at the same time as their husbands, Maestas said. Since women in heterosexual couples typically marry men two or three years older, that means married women leave the workforce at younger ages.
Women face extra risks
Earlier retirements also mean less time to save for retirements that can stretch decades. That should give women pause, said Jean Setzfand, senior vice president of programs for AARP.
"We live longer. We spend more years in retirement. There are more years we have to consider financing," Setzfand says.
Women's longer life expectancies mean they're likely to outlive their husbands, and they're at greater risk of outliving their savings. Women are 80 percent more likely than men to live in poverty after age 65, according to the National Institute on Retirement Security.
Social Security checks, if they're big enough, can be a powerful antidote to late-in-life poverty. Social Security benefits can't be outlived, reduced by stock market downturns or stolen by fraudsters, Maestas notes.
Delay Social Security, if not retirement
People don't have to claim Social Security when they retire, although many do. Thirty-nine percent of women and 35 percent of men in 2017 filed at the earliest age, which is 62, according to the Center for Retirement Research at Boston College. That locks them into checks that are significantly smaller than if they'd waited a few years.
Benefits rise by about 7 percent each year between age 62 and full retirement age, which is currently 66. After that, checks increase by 8 percent each year until benefits max out at age 70. A $1,000 monthly benefit at 62 could be over $1,300 at 66 or over $1,700 at 70, even if someone stops working.
No other investment can offer that kind of guaranteed return, which is why planners often encourage their clients to tap other retirement funds if that allows them to delay claiming Social Security.
It's not just about money
Financial considerations are just one part of the decision, according to financial planners. Couples also have to consider the emotional and psychological issues of retiring together or apart.
"The beginning of retirement is an exciting time, and many couples enjoy starting that journey together," said Stephanie Mushna, a certified financial planner in Grand Rapids, Michigan.
People approaching retirement age are often keenly aware that their time on earth, and their good health, won't last forever. That can make it harder to stick it out, especially if it's at a job they don't like. But working even a year or two longer can have a dramatic impact on the viability of a couple's financial plan and the amount they can spend in retirement, planners say.
Other options are stepping down to a lower-stress job or one with more flexibility. Instead of traveling full time with a retired spouse, wives may be able to schedule some extended vacations, Setzfand suggested.
That assumes, of course, that women can find such jobs. Many of the women who will depend most on Social Security may be locked into jobs with little flexibility, she noted. Health concerns and caregiving for family members also can push women out of the workforce earlier than they expect.
Maestas understands that not every married woman wants or will be able to keep working, but she hopes her research will at least prompt couples to discuss their options.
"It often does make sense to at least delay claiming Social Security," Maestas said. "But there's not really one right answer for everyone."
This column was provided to The Associated Press by the personal finance website NerdWallet. Liz Weston is a columnist at NerdWallet, a certified financial planner and author of "Your Credit Score." Email: email@example.com. Twitter: @lizweston.
Related link: NerdWallet: How much do you need to retire?