While congressional Republicans are busy working on their secret health care bill, President Donald Trump is already undoing pieces of Obamacare on his own. He pledged during the campaign that he would roll back a regulation issued as part of the Affordable Care Act that requires contraception to be covered without co-pay in insurance plans. The rule had angered religious employers, who objected to, they say, being complicit in providing birth control to their employees.

Despite numerous workarounds offered by the Obama administration, the Trump administration is reportedly undertaking a sweeping change that will allow virtually any employer to wriggle out of the mandate. There would be no requirement that they find another way to provide contraception, such as through a third party. Trump’s reversal would thus risk any employee’s free coverage and potentially put them back on the hook for hundreds of dollars a year. Before the ACA, 85 percent of large employers’ plans covered birth control, but most required a co-pay and deductibles. Without the mandate, thousands of employers could quickly rescind the benefit.

States will not be outdone by the federal government, however. The Missouri Senate just approved a bill that includes a provision rolling back employment protections in St. Louis for women who use contraception, which was tucked alongside a number of other attacks on reproductive rights. The legislation would make it perfectly legal for an employer to fire or refuse to hire someone because she uses birth control.

Allowing employers to discriminate against employees for using contraception, or to exclude contraception coverage in health plans, isn’t just objectionable because it gives bosses the power to dictate private aspects of their employees’ lives. It’s economic nonsense. The economy, and therefore every employer in the country, owes a huge debt of gratitude to contraception. The pill played a central role in allowing women to flood the workforce, improving prospects for us all.

Research has definitively established that the higher the female fertility rate, the lower women’s chances of working in paid jobs. It’s a lot harder to find and hold down work if you have multiple children to care for. Up until the 1960s, women tended to drop out of work once they hit their prime childbearing age.

That’s particularly true if you aren’t even able to control how many children you have and when. While the FDA approved a birth control pill in 1960, widespread use didn’t really get going until the late 1970s, after state laws were relaxed regarding who could actually obtain it. By 1973, nearly 70 percent of married women used the pill, which climbed to about three-quarters in the late 80s, where it has stayed since.

The economic effect of that change was enormous. Once women started controlling their own bodies, and their fertility rates fell, their employment rates skyrocketed. Research by economists Claudia Goldin and Lawrence Katz has found that, starting around 1970, the pill played a big role in women graduating college more frequently and marrying later. Both of those changes allowed them to have careers. Women were freed up to seriously pursue education and paid work without the risk that an unexpected baby would stop them in their tracks.

“The pill directly lowered the costs of engaging in long-term career investments by giving women far greater certainty regarding the pregnancy consequences of sex,” the authors write. This was true especially for professional careers like law and business that require extensive training. Why begin a law degree if a child could easily interrupt it? The authors found that more than 30 percent of the increase in women holding these jobs was thanks to the pill.

Another paper gets even more specific: Legal access to the pill before women turned 21 both increased how many women were in the labor force as well as how much they actually worked. Access to the pill reduced the likelihood that a woman would have a baby before the age of 22 by 14 percent. That, in turn, increased young women’s labor force participation by 7 percent. The women who first had legal access to the pill because of their states’ laws worked 650 more hours than their peers who only got it later.

The benefits of all this work experience accrued to women themselves. The women who had early access to contraception made 8 percent more by the age of 50 than the others. The pill is responsible for about a third of the closure in the gender wage gap that was achieved by 1990.

But the benefits also accrued to everyone. Between 1972 and the early 1990s, the share of women in their prime working age who were in the workforce rose from 72 percent to nearly 84 percent. Had that not happened, the economy would have been about 11 percent smaller in 2012.

Not all of that, of course, was thanks to access to contraception. But birth control played a huge role. Women’s careers, and the entire economy, would look very different without their ability to use it.

This remains true today. The ubiquity of birth control—contraception has now been used by nearly 100 percent of sexually active women—means that its impact is no longer quite as transformative, but studies of contemporary women find that having fewer children still increases their participation in paid work, while the inverse is also true. In a survey of women who use birth control, about half said they need it because it allows them to complete their education or find and keep a job.

Employers may not feel like any of this is their problem. But the potential pool of hirable employees would shrink considerably if women weren’t able to access contraception reliably and were constantly dealing with unwanted or unexpected pregnancies. And every American business benefits from the size and strength of this country’s economy, at least some of which is thanks to women who popped the pill and got a job.

There are no good reasons to let employers decide whether employees can or can’t use contraception. The list in favor of giving women the ability to control their reproduction, on the other hand, includes bosses’ own bottom lines.