Over the last decade, the internet has made it much easier for students to apply to college, especially thanks to services like the “Common App.” For the nearly 700 schools now part of the Common Application—the nation’s leading standardized online college-application portal—students can browse by name, state, or region, by the type of institution (public or private), and by whether it’s co-ed or single-sex. Clicking on a college takes students to a brief profile of the school and then an invitation: “Ready to apply?”

And now that students can apply to more colleges with the click of a few buttons, they are doing exactly that. In 2013, according to the National Association of College Admissions Counselors (NACAC), 32 percent of college freshmen applied to seven or more colleges—up 10 percentage points from 2008. Almost all of this growth has been online. In the 2015-16 admissions cycle, over 920,000 students used the Common App, more than double the number in 2008–09.

On the one hand, the internet has been good news for college access. Officials at the Common App, for example, say 31 percent of the college applicants who used the portal in 2015–16 were first-generation students. Students and their families are also now smarter consumers of what’s likely to be among the biggest ticket items they will ever buy: a college education. The internet has also been great news for college marketing departments, which can now reach many more students—and more cheaply—than they could via old-fashioned snail mail.

But the growing piles of applications are also causing problems—both for colleges and for students. While schools might welcome the rush of national exposure from a broader pool of prospects, they also increasingly face the problem of sorting out qualified, serious applicants—students who not only have the right academic chops but would actually enroll if accepted—from the scrum. And so long as the sheer volume of applications continues to rise, the odds of colleges’ guessing wrong rise too—which, in fact, is what’s happening, with dire consequences.

For students, the flip side is how to rise above the growing tide of competition, or how to hedge their bets if they don’t. For middle-class and upper-income students, this means more hassle, anxiety, and expense. But for lower-income students, it means barriers that could prove insurmountable. While the college-admissions process has long been a game that favors those who know the rules, a crowded market is just one more way of stacking the deck against those who don’t or can’t afford to play.

For many schools, the national applicant pool made available by the internet has been a great way to raise their “selectivity”—a metric that matters greatly for traditional college rankings, like those of U.S. News & World Report. The lower the percentage of students admitted, the more “selective” the college. This means a school that admits the same number of students every year can appear more “selective” if its applicant pool is bigger and more students are rejected.

Many schools discovered that online applications, including the Common App, were an easy way to help grow the pool of prospects. The Common App, for example, offers a standardized application, “auto-fills” students’ personal data from form to form, and offers tools to help manage submissions. Adding new schools to a student’s wish list can be accomplished with a click. At some schools, simply replying to an email is enough to make a student an applicant. “As colleges moved to online applications, many of them looked to streamline the process so it wouldn’t be as cumbersome for students,” says David Hawkins, the executive director for educational content and policy at NACAC. “A lot of colleges also found that it resulted in a lot more applications coming in.”

At the University of Colorado Boulder, for example, freshman applications jumped by roughly 28 percent in 2013, the year the university joined the Common App, and have continued to grow, according to the admissions director, Kevin MacLennan. While the school saw 22,437 applications in 2013, it fielded 34,100 applications this year. Most of that growth has also come from out-of-state and international students, from whom applications have risen by more than 10,000 since 2013. “The quality of our applicants has gone up,” MacLennan says. “[It has] increased in grade-point average and high-school rank, but in test scores as well.”

For smaller schools, a digital admissions marketplace has helped to shortcut their path into the national or international spotlight. “Who knew about Macalester [in St. Paul, Minnesota] in the early 1990s, or Rollins [outside Orlando, Florida]?” says Jeff Knox, an educational consultant who works with the Bethesda, Maryland–based firm PrepMatters. “But they’re becoming really popular.”

The concern for colleges is that selectivity and national reach aren’t the only metrics that matter. Just as critical is “yield”—the share of accepted students who actually enroll. It’s what colleges use to project their revenues and manage their finances, and miscalculations can be fatal. Too few students—too low a yield—can spell shortfalls that lead to budget cuts, fewer classes, or even faculty layoffs. In 2013, for example, Joseph Urgo, the president of St. Mary’s College of Maryland, resigned after the school fell short of its enrollment targets by nearly 25 percent. On the other hand, too many enrollments could mean not enough student housing or financial aid. At Temple University earlier this year, an unexpected number of acceptances for the incoming freshman class—a higher-than-expected yield—caused the school to exceed its financial-aid budget by $22 million and resulted in the abrupt ouster of both the provost Hai-Lung Dai and the president Neil Theobald.

Most schools, however, are having trouble finding the right students. In fact, despite the online application boom, schools are in crisis around yield. NACAC’s State of College Admission survey found that the average four-year college yield rate was 35.7 percent in 2013—down from 48.7 percent in 2002. At the University of Colorado Boulder, for example, MacLennan, the admissions director, says that while about half of the in-state students who are accepted are likely to enroll, the school yields one out-of-state student for every five or six offers—a yield rate of roughly 20 percent. At Drexel, a university in Philadelphia which was one of the schools that pioneered the reply-to-this-email-and-you’re-an-applicant trick, the school’s yield rate plummeted to as low as 8 percent despite a surge of applications. The college has since taken steps to stem the flood by returning to a more traditional process.

The cause of all this volatility is a problem in the college-admissions marketplace that the Stanford University economics professor and Nobel laureate Alvin Roth calls “congestion.” “Congestion is what happens when you have a lot of people in the market and too many offers,” says Roth, the author of Who Gets What—and Why: The New Economics of Matchmaking and Market Design. “It’s gotten easier to apply to colleges, but now colleges get many more applicants. That changes the ‘signal to noise’ ratio.” It’s an ironic and unintended consequence of college admissions on the internet: The seeming efficiency of online applications means less efficiency overall.

But if colleges are aiding and abetting this market congestion, a big share of the burden of coping with it has fallen on prospective students, the wealthiest of whom are best equipped to navigate the marketplace.

For example, many schools are increasingly relying on “early decision” and other tools to secure commitments from top recruits. According to NACAC, nearly half of colleges said they admitted more students through early decision during the 2013-14 admissions cycle, while the number of early-decision applicants also grew. While colleges enjoy the certainty of a student’s commitment to their school (and the resulting boost in yield), the downside for students is less ability to compare financial-aid packages across schools. As a result, affluent students are the most likely to apply early decision, especially to more selective schools. A 2016 investigation by The Washington Post found that many top schools filled as many as half of their freshmen classes with early-decision students, effectively shutting out lower-income students from a big part of the applicant pool.

The same bias afflicts schools’ increasing reliance on “demonstrated interest”—another tactic colleges use to raise their yield by looking for proactive indications that a student will enroll if accepted. “It used to be that applying was how you demonstrate interest, but it’s just not the case these days,” says Knox, the educational consultant. In fact, some admissions officials say that “demonstrated interest” is now almost as important as an essay or teacher recommendation in determining who gets admitted.

The best way for a student to demonstrate interest is to visit the campus. The problem is that while a college tour might be a rite of passage for middle-class and affluent students, it’s far less feasible for students without the resources or support to visit prospective schools.

In addition to campus visits, colleges are also creating elaborate systems to track and measure students’ interest in other ways. “Colleges now have these sophisticated electronic dashboards so that every interaction with them is logged into the system,” says the NACAC’s Hawkins. “Even something as simple as liking a college on Facebook—that’s a little checkmark in your dashboard. It’s part of a very comprehensive recruitment strategy that colleges are now engaged in because of this uncertainty around yield.”

“We also know every interaction students have had with the university,” says MacLennan, from the University of Colorado Boulder. “Maybe they’ve come in and visited the campus for an information session. Maybe they’ve toured the campus. Maybe they’ve shown up on a high-school visit or brought their parents to one of our hotel programs. We have a record of not only how many times we have contacted them but how many times they’ve contacted us, and that will begin to show the strength of their interest.” These records can begin as early as ninth grade.

Of course, most students have no idea that this is how colleges are judging them. Some do, however, because they have the means to hire private educational consultants who can explain the rules of the current admissions marketplace. “One way to tell that the market is dysfunctional is if you have to hire a guide,” says Roth, from Stanford. “The college-admissions process at one point was supposed to be something that high-school seniors could do for themselves.”

According to Mark Sklarow, the CEO of the Independent Educational Consultants Association (IECA), the number of private educational consultants has skyrocketed over the past decade. Sklarow estimates that there are 5,000 full-time consultants nationwide, including the roughly 1,500 who are members of his organization, plus another 10,000 to 15,000 consultants working part-time. Thirty years ago, Sklarow says, educational consultants numbered less than 100 and catered exclusively to the highest-income families. Today, he says, the typical client is a middle-class or upper-middle-class student in a public school. Despite the mainstreaming of private counseling, it’s still expensive. Sklarow says that the typical cost of hiring a consultant to help with college admission is about $4,500, spread out over three years, beginning in a student’s sophomore year. While some consultants charge a flat fee, others charge an hourly rate, which averages $160 nationally.

In addition to the perceived complexities of applying to college, the shortage of public-school counselors is what’s driving demand for private admissions consultants. “There’s an increased need for counseling and a decrease of availability,” Sklarow says. The average ratio of students to school counselors in public schools was 491 to 1 in 2014, according to the American School Counselor Association, up from 460 to 1 in 2012. According to a study by the nonprofit CLASP, high-poverty public high schools are about twice as likely as other schools to have no counselor at all. Instructively, many private admissions consultants have gotten into the business because their jobs as high-school guidance counselors were eliminated.

The confusion caused by the congestion in the college-admissions market, together with a shortage of guidance counselors and the emerging dance around “demonstrated interest,” could exacerbate the problem of “under-matching,” where high-quality lower-income candidates are channeled into less-selective schools, where their chances of graduating are lower and their lifetime earnings lower even if they do graduate. But there are growing risks for other students, as well, because there’s no obvious endpoint for the escalation in applications. As long as students continue to apply to more and more schools, the noise in the market and its attendant uncertainties will increase. This, in turn, prompts yet more applications by students anxious to hedge their bets by casting a wider and wider net. It’s a deepening, bottomless spiral.

Unless the colleges choose to stop it.

One way to do this, says the Washington, D.C.-based educational consultant Shelley Levine, is for colleges to stop marketing to students just to pump up their application numbers and “selectivity.” For one thing, this system is unfair to students. “You wouldn’t believe the students who come into our office saying they’ve received letters from Yale and Harvard and Princeton and Washington University saying they’re just the kind of candidate the school is looking for,” she says. “I say stop giving false hope.”

But the only way for this to happen is for colleges to abandon their obeisance to “selectivity” and other metrics that distort students’ choices toward “prestige” and away from the more important consideration of fit. Given the losing battle that colleges seem to be engaged in over the question of yield, this is one place where what’s best for students might be the right answer for colleges, too.

This post appears courtesy of Washington Monthly.