America, it seems, is short on babies. While most developed countries watched their birth rates gradually decline over the 1990s and 2000s, U.S. birth rates remained high and then plummeted over the past 10 years—from 70 births per 1,000 women in 2007 down to a record low of 59 in 2018.

The response to these declines has been such that the Centers for Disease Control and Prevention (CDC) might as well retitle its Vital Statistics Report “Everybody Panic.”

There has been widespread public consternation that a low birth rate will put the economy in peril, with some imagining that the United States will soon face Japan’s population crisis and fretting for the future of the American family when having children is no longer a priority.

A priority for women, that is, because apparently women are entirely responsible for determining when and how many babies are born.

All of the blame for the decline in birth rates has been laid at the feet of women—who by all appearances are blatantly ignoring the warnings of everyone that if they delay having children, they might not have them at all. This despite good evidence that if women are delaying having children, it is in part because men are delaying even longer.

Much has changed in the world in recent decades, but the one constant is that making babies is a two-body problem, even if those bodies aren’t involved in the childrearing. And for the majority of heterosexual women, who do not want to raise children alone, the decision of when and how many children is subject to a binding constraint—finding a suitable and willing partner to father those children.

The share of childless people who say they want to have a baby in the future decreases with age. This stands to reason. Most people who say they want children have them when they’re young. As such, this shrinks the pool of childless, child-wanting people. In addition, the realities of parenthood are more apparent at age 35 than they are at age 18, and the desire to parent changes over our lifetimes, sometimes in unpredictable ways.

“ if we want to understand why there are fewer babies being born, we need to stop obsessing over the behavior of women—which isn’t really that complicated—and start trying to understand the behavior of men. ”

What is surprising is how much men and women differ in their intention to have children over their lifetime. When I look at nationally representative data, the share of single childless men who say they intend to have a child exceeds that of women at every age except when women are in what we think of as prime childbearing age—25 to 34 years old. Younger men are more likely to say they intend to have children, 89 percent of men to 85 percent of women. Older men are too, with 46 percent of men aged 35 to 44 saying they intend to have children compared to only 38 percent of women at that age. A full 32 percent of single childless men aged 45 to 54 believe they will have a child in the future.

What is even more interesting is that compared to women who want children, men who want children are much more likely to say they don’t want them anytime soon.

For example, 34 percent of single childless men age 25 to 34 who want children want to wait at least five years before having them, compared only 15 percent of women who want the same. Even men a decade older are willing to wait to have children—61 percent of 35- to 44-year-olds would like to wait two to five years, and 19 percent would like to wait more than five years, compared to 51 percent of women who want them within the next five years.

These decisions of men are understandable. While women are incessantly reminded that their fertile years are limited, men are fed a narrative that they can set their own schedule for parenthood. And if women are now delaying having children to an older age, at least part of that explanation is that their potential partners are delaying even longer.

Research shows that men consistently overestimate how easy it will be to have children when they are older and consistently underestimate how difficult it will be for medical interventions to overcome fertility problems. Men’s fertility decreases as they age. And even if declining fertility for men wasn’t the issue, men are also subject to a two-body problem. It is easy to say men can have children at any age, but even a fertile man will be childless unless he finds a fertile woman willing to be bear his children.

Despite perceptions, very few women in their thirties are looking for older men to marry. On average, women want husbands who are only slightly older than themselves (about 3.5 years older), and the average age difference between heterosexual married couples is just over two years.

The hard truth is that if a man cannot find a 35-year-old woman to start a family with when he is 35, he is probably not going to find a 35-year-old woman to start a family with when he is 50.

Women alone are not responsible for the end of babies. And, truth be told, the decline in fertility is more the result of declining teen births (down 7 percent in 2018 alone) than it is older women putting off childbearing until it is too late to have them.

The decline in births is probably not the social crisis that so many imagine it to be—we are not Japan, and the American family will likely survive, albeit with fewer children. But it is concerning that people are having fewer children than they desire, reflecting the possibility that the system has been rigged to make it difficult to achieve what many believe to be one of the greatest joys in life.

We don’t actually know how many children American men desire, as the CDC only reports on the fertility desires of women. But if we want to understand why there are fewer babies being born, we need to stop obsessing over the behavior of women—which isn’t really that complicated—and start trying to understand the behavior of men.

I won’t hold my breath. When it comes to the business of having, or not having, babies we seem to be remarkably unwilling to admit that men play any role at all.