It’s always nice to get something for nothing, and given astronomical college prices and the seemingly self-evident value of education, free college sounds unimpeachable. But nothing is truly free—indeed, the unintended costs can be crippling—and just because something is called “education” doesn’t mean you are learning very much.

“Free” would have to be paid for with tax dollars, and looking at colleges’ current tuition and fee revenue, and income directly from government, gives a rough sense of how much it would cost. Using the most recent federal data, it comes to roughly $339 billion annually, or about $1,360 for every adult in the United States. If you live to age 75, and pay that annually in taxes starting at age 18, that’s $77,500—not free at all.

And not fair. Why should people who want to go to college get it paid for in part by people who pursue on-the-job training or other forms of noncollege education? Indeed, why should anyone get a degree to increase their lifetime earnings on the backs of taxpayers?

This is not to defend the current pricing model. Government “aid” to make college more affordable has actually fueled the tuition skyrocket.

In the 2015–16 academic year, Washington delivered about $139.6 billion to students, up from $53.1 billion, adjusted for inflation, 20 years earlier. That has enabled colleges to raise their prices at breakneck rates, ironically creating hyperinflated prices most hurtful to the low-income people aid was supposed to help.

Perhaps more damaging than the financial cost, however, has been the upcredentialing created by massive subsidies, forcing many Americans to earn degrees just to stay in one place in the job market. Subsidies have encouraged more people to go to college, enabling employers to demand degrees even for jobs that haven’t changed, forcing more people to go to college, and so on. Free college through even greater government intervention would almost certainly intensify this vicious cycle.

This might be tolerable if additional credentials carried commensurate increases in useful knowledge and skills. They do not.

According to the National Assessment of Adult Literacy, literacy rates for people with bachelor’s and advanced degrees plummeted between 1992 and 2003 (the only years studied). Among those whose highest attainment was a bachelor’s degree, the share who hit prose proficiency dropped from 40% to 31%; for people with graduate studies, it fell from 51% to 41%. Little wonder: As reported in the book “Academically Adrift,” the hours full-time students spent studying or in class dropped from about 40 a week in the early 1960s to about 27 today.

The dearth of useful learning may be one reason that earnings for bachelor’s and advanced degree holders ages 25 to 34 dropped between 2000 and 2015.

There may be another major cost to “free.” Our long tradition of paying customers, private funding and autonomous institutions has made ours the premier college system. The United States is home to the majority of the world’s Nobel laureates, is the top destination for students studying outside of their home countries, and U.S. institutions predominate at the top of international rankings.

“Free” higher education would stultify this—eliminating the need for schools to compete for students to bring in revenue, and inevitably transferring decision-making from institutions to the government bureaucrats paying the bills.

A college education seems financially daunting, but making it free is not the answer. The key to quality, affordable education is to subsidize neither students nor schools, but have people pay with their own money, or money they are voluntarily given or lent, while leaving institutions free to establish their own prices, aid systems and rules. Then astronomical pricing and credentialism will wilt, without killing the dynamism that sets U.S. higher education apart.