American exceptionalism can sometimes be quite bleak: The United States is the only wealthy country in the world without a national program for paid parental leave.

The U.S.’s best chance yet of giving up this dismal distinction might be slipping away. The $1.8 trillion domestic-policy bill that’s making its way through Congress initially was going to include funding for 12 weeks of paid family and medical leave, which would cover a share of people’s wages as they take time off work to care for their loved ones (newborns included) or themselves.

But because of hesitations on the part of moderate Democrats (and total resistance on the part of Republicans), the proposed leave went from 12 weeks to four weeks to zero weeks, when the provision briefly dropped out of negotiations entirely. Last week, Democrats in the House reinstated four weeks of leave, but whether that will make it into the final version of the bill that the Senate votes on is unclear.

The bill does include other policies that would be a huge help to time- and cash-strapped families, including funding for universal pre-K and an extension of the expanded child tax credit. But losing family and medical leave would be dispiriting for many Americans who need it, especially after the coronavirus pandemic has underlined the strain that the lack of such a policy puts people under, particularly parents and working women. “At a time when recognition of the need for paid leave is higher than it’s ever been, for it to be seen as not essential or too expensive just seems crazy,” Richard Petts, a sociologist at Ball State University who studies parental leave, told me. Watching the political process play out, he said, “I just want to bash my head against the wall.”

[Read: The conservative argument over paid family leave]

The prospect of missing out on parental leave is particularly exasperating to experts like Petts given that researchers have been documenting its benefits for decades. “This is not new information, by any means,” Petts said of the policy’s positive effects.

Paid leave is also not nearly as controversial around the globe as it is in the United States—186 other countries, for instance, provide some amount of paid maternity leave. “If Brazil can do this with its GDP, please explain to me why the United States can’t do this, with its GDP,” Jennifer Glass, a sociologist at the University of Texas at Austin, told me. “Sad” and “depressing” were two words she used to describe what it has felt like, as an expert on work-family policies, to watch the U.S. go on and on without a national leave program.

To a large extent, the benefits of parental leave are self-evident. Healing from giving birth usually takes at least six weeks, and “returning to full-time work when the newborn and primary caregivers are still adjusting to one another, and a birth mother has not yet recovered physically from childbirth, is a terrible idea,” Glass said. But that’s what many mothers and most fathers do anyway, because they can’t afford not to. (Per government data, only 23 percent of American workers have access to paid family leave through their employer.)

Over the past several decades, research has established further benefits that fall under several, often overlapping, categories. First, leave is good for families’ physical and mental health. Babies whose parents take leave are more likely to get their vaccinations on time, more likely to be breastfed, and less likely to go to the hospital with an infectious disease. And on top of giving birth mothers time to physically heal, taking leave is linked to better mental health for mothers, both when they take it and when fathers do.

Leave is also beneficial for family relationships: Dads who take leave tend to go on to be more involved in their kids’ lives, and their partnerships tend to be more stable. “This sets up a developmental trajectory for both parents and children,” Kathleen Gerson, a sociologist at NYU, told me. Fathers “develop stronger, longer-term ties to their children, and parents see parenting as a more collaborative and shared endeavor.”

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Third, parental leave helps families financially. Currently, many new mothers who take time off lose or leave their job, and the employers they turn to afterward may pay them less or view their new child-care obligations as a liability. Meanwhile, Glass said, “paid parental leave keeps parents employed during that crucial transition to parenthood,” preventing a steep drop in pay and a period of employment instability. That continuity—both in employment and in income—can make a difference in children’s lives, particularly those with parents in low-paying lines of work. (Kids benefit from parental leave, but they also benefit from family and medical leave in a broader sense, because many people who need to take time off work to care for loved ones or themselves are supporting children as well.)

Clearly, implementing a policy that captures some of these benefits is possible, even for countries with far less wealth than the United States has. When I asked several experts what they thought was behind America’s unique lack of paid leave, some brought up the country’s low rates of union membership and general deference to employers’ desires. But the most common theory was that a program that, however briefly, pays people to not do their jobs seems to violate the (sometimes pernicious) American virtues of self-sufficiency and hard work. This logic, though, can be self-defeating, in the sense that paid leave can help mothers stay in the workforce, and its lack can push them out of it. (This faulty rationale also ignores the very real work of parenting and other caregiving.)

Perhaps unsurprisingly, the four weeks of leave currently under consideration is, by global standards, paltry. In an interview, Vicki Shabo, a senior fellow at the left-leaning think tank New America, called it “a very American period of time”: Four weeks is less time than it typically takes to recover from birth, and is far less than the worldwide averages, which are about seven months of paid leave for mothers and four months for fathers in the countries that provide it.

Despite America’s historically underwhelming family policies, some of the experts I spoke with looked back on the past few decades with some optimism. Shabo said that when she started focusing on these issues in 2010, only two states had paid-leave programs. Now nine states and the District of Columbia do, and she expects that even if family leave is cut from the congressional bill, more states will put their own policies in place.

Gerson, the NYU sociologist, has been researching families and work since she was a grad student in the 1970s. “One major shift that we now take for granted is that we are no longer arguing about whether or not mothers should work—that was the dominant debate in the late 20th century,” she said. Now the debate is over how to support working families. “I find that very heartening,” Gerson told me. “I’m optimistic about the long run, and that helps me deal with the short-run setbacks.”