Why is U.S. fertility declining? That’s what Morning Consult for The New York Times tried to find out with a survey Thursday.

The survey included 1,858 men and women between the ages of 20 and 45. Reasons for fewer children vary. But concerns about money and personal goals play a large part.

Many Still Want Kids — They Just Aren’t Having Them

It’s not that most Americans don’t want children. A 2013 Gallup poll found that most adults hope to have kids if they don’t already. And apparently, many hope for a lot. Or at least they tell pollsters that.

A new Gallup poll found Friday that 41 percent of Americas say three or more kids is the “ideal family size.” As the report states, that’s “the highest Gallup has seen on this measure since 1997.”

Fifty percent of Americans say one or two children is ideal, the poll found. So the average ideal family size for Americans is 2.7 kids. But adults aren’t having that many.

“About a quarter of the respondents who had children or planned to said they had fewer or expected to have fewer than they wanted,” the Times reports of its survey respondents. Why the disparity?

These respondents largely blame finances. Sixty-four percent said child care is too expensive. Nearly 50 percent said they are worried about the economy. Other reasons for having fewer children than desired included not enough or no paid family leave (39 and 38 percent). Concerns about climate change and population growth were also significant (33 and 27 percent). Another reason was finding a partner too late in life (34 percent).

Leisure Time Biggest Concern For Those Who Don’t Plan on Kids

And what about those who don’t plan on having any kids, ever? The biggest reason (36 percent) cited in the survey was a desire for leisure time. The next biggest reason (34 percent) was lack of a partner.

Finances were still a significant theme, however. Thirty-one percent said they couldn’t afford childcare. Other money reasons included worrying about the economy (23 percent), having too much student debt (13 percent), and not being able to afford college (11 percent).

Financially speaking, it’s still tough for many young adults. The Times reports that the current generation will likely earn less than their parents. In previous generations, it was normal for young adults to end up making more than their parents. Millennials are also burdened with record amounts of student debt.

“Wages are not growing in proportion to the cost of living, and with student loans on top of that, it’s just really hard to get your financial footing — even if you’ve gone to college, work in a corporate job and have dual incomes,” 29-year-old David Carlson told the Times.

Delayed Motherhood and Working Women

And that’s one reason many couples delay childbearing. But delaying contributes to lower fertility rates. A woman’s fertility declines dramatically in her 30s.

Philip Cohen, a sociologist who spoke with the Times, said women’s changing circumstances also play a big factor in declining fertility. “There is no getting around the fact that the relationship between gender equality and fertility is very strong,” he said. “There are no high-fertility countries that are gender equal.”

Economist Lyman Stone looked into the relationship between gender equality, fertility and pro-family policies last year for Institute for Family Studies. Some claim that while more gender equality initially leads to a fertility decrease, it eventually causes greater fertility. Studying several developed nations that have “pro-natalist” policies, he found that the real issue is more complex.

Pro-natalist policies, like financial incentives, do boost short-run fertility. But “this could just be a timing shift,” Stone warns. “Maybe people have kids earlier but don’t increase total childbearing.”

That leaves Americans with more questions. It’s obvious from Gallup and the Times that Americans still at least claim to want kids. But they may be delaying, having fewer than desired or forgoing altogether thanks, in large part, to finances. (It’s worth noting that according to some indicators, fertility may not be declining as much government numbers state.)

“Our politicians have critically underestimated the scale of the fertility collapse in the United States,” Stone wrote last September, “along with the price tag they’ll face if they want to fix it using financial incentives.”