For decades, the telltale markers of extreme wealth were easy to spot: the second home, the luxury cars, the Ivy League education. A new analysis of Federal Reserve data points to a subtler one — the third child.

Mike Konczal, vice president of policy and research at the Economic Security Project and a former White House economist, examined households headed by 45- to 64-year-olds in his analysis of the Fed's Survey of Consumer Finances — the central bank's triennial survey of American household finances — pooling five surveys conducted from 2013 through 2025. He found that 49% of top-1% earners have three or more children, compared with about 40% of the rest of the top 10%.

The gap is not driven by very large families. Households with four or more children are roughly as common in both groups, meaning the difference comes down to the third child specifically: 34% of the top 1% stop at exactly three, versus 24% of the merely affluent.

The rich themselves haven't changed. Since the 1990s, families with three or more children have become less common in the overall population and among the rest of the top 10%, while the top 1%'s share has barely moved. “What's new is that it has become rarer for everyone else,” Konczal writes.

Big families thin out noticeably in the upper middle class. When families are ranked by wealth rather than income, only about a third of those richer than roughly three-quarters of Americans their age — but still well short of the top — have three or more children. That is well below families further down the wealth ladder. In the top 1% by wealth, half do.

Complicating the picture, many of these families earn too much to qualify for federal child care subsidies, capped at 85% of a state's median income, yet not enough to simply hire their way around the problem.

Elaine Shi and her husband once thought they might have four children. They stopped at three. Asked how much cost factored into the decision, Shi, the CEO and co-founder of body-composition scanning company BodySpec, answered flatly: “None.” What settled it was their third child's “firecracker personality,” along with her health during each pregnancy.

Shi does not see that income divide among the people she knows. “Candidly, this has not been my experience,” she says. What stands out to her instead is timing: “Relatively few of my peers in our late 30s have chosen to have three children because they started having the first one relatively late in life.”

Americans still say they want three

Big families were once ordinary. In 1976, about two-thirds of mothers in their early 40s had three or more children; by 2016, 38% did, according to Pew Research Center.

The U.S. fertility rate, close to two children per woman in 1995, hit a record low of 1.57 in 2025, according to a Wall Street Journal calculation using federal data — well below the roughly 2.1 births per woman long viewed as the level at which each generation replaces itself.

Americans still say they want more: 42% called three or more kids ideal in Gallup's July 2025 poll. But more than 7 in 10 say raising children is unaffordable for most people, according to BYU's 2025 American Family Survey.

Where the money goes

Shi's third child arrived at a hectic moment. Her older two, about two years apart, were starting school, and their needs were diverging.

“It didn't seem fair to drag an infant along to every gymnastics and swim class, nor did it seem fair to forego those kinds of activities to stick to a baby's nap schedule,” she says. She was also mid-fundraise and needed to get back to work quickly. “So we ended up investing in multiple caregivers to better meet everyone's needs.”

The biggest financial change in going from two kids to three, she says, was “definitely childcare.”

Most families cannot hire their way out. Full-day care for one child cost $6,552 to $15,600 a year in 2022 — 8.9% to 16% of median family income — according to the Labor Department. And that is for a single child. By one LendingTree estimate, a two-child household needs to earn $400,000 a year for childcare to be affordable.

A third child often means a bigger house, too. The typical existing single-family home sold for $412,500 in 2024, about five times the median household income, according to Harvard's Joint Center for Housing Studies. In the 1990s, the ratio was closer to three times.

Why it matters beyond the family budget

The United States recorded just over half a million more births than deaths in 2025, and projections from the Census Bureau and the Congressional Budget Office show that cushion ending within the next decade, the Wall Street Journal reported. After that, population growth would depend on immigration.

Economists warn that fewer births mean a smaller future workforce, slower growth and more strain on Social Security.

Konczal cautions that his numbers show a correlation — but it is the one you would expect if money solves the hard parts of raising children. He argues that some of what money buys the rich, such as stability and support, could be offered to families now, through policy aimed at the years when children are young and budgets are tightest.

Shi's own fix is more about time than money. She and her husband run BodySpec together, and their favorite workday, she says, is Saturday. The office is empty, and one of the kids usually tags along — most often her son, the middle child. He gets to build a LEGO set without his sisters taking it apart, then has lunch alone with his mom.

“Nobody told us this counted as work-life balance, but it's the closest thing we've found,” Shi says.

This story was originally featured on Fortune.com.