It’s June, and millions of high school seniors have chosen a college — a choice often made with the help of college-ranking guides like Barron’s or U.S. News and World Report. Unfortunately, families may not know higher education’s dirty secret: these rankings mean a lot less than you might think.

More and more schools are entering the top tiers of competitiveness rankings in the respected Barron’s Profiles of American Colleges, largely because of application and grade inflation — not increased academic quality. Indeed, between 1991 and 2011, the number of schools ranked by Barron’s as “most competitive” increased from 44 to 87. While the usual suspects maintained their high ranking (Harvard, Princeton, Yale, etc.), the list grew to include schools that were previously ranked at least two tiers down, like George Washington University and the University of Southern California — and the share of institutions in the top three categories has risen from less than a quarter to nearly a third.

Barron’s ranking criteria haven’t changed over time, so what explains this shift? It turns out that two of these criteria, college selectivity and high school grades, have been subject to rampant inflation. 

Overall, college applicants are applying to more schools than in the past. Twenty years ago, only 9 percent of college freshmen had submitted seven or more applications for admission. In 2010, that number had nearly tripled to 25 percent, creating a boom in total applications. As schools receive — and, necessarily, reject — more applicants, they appear more competitive.

Meanwhile, since the early 1990s, high school GPAs nationwide have steadily risen, from an average of 2.68 in 1990 to 3.0 in 2009 — even as long-term assessment data from the 2008 National Assessment of Educational Progress show no actual improvement in math or reading scores. In other words, although high school students seem to be doing better in school, there’s no evidence they actually know more. The result is that institutions can boast student bodies with ever-more-impressive high school transcripts, no matter how badly educated their grads may be.

Applicants and their families should be wary of letting these rankings serve as the main criteria in their college decisions. Though 87 schools currently occupy the top category on Barron’s list, they do not necessarily offer teaching or instruction of similar quality. We know, for example, that graduation rates vary dramatically between colleges and universities that occupy the same tier in these rankings.

Faux exclusivity might be good for a school’s endowment or parents’ bragging rights, but it too often encourages families to overpay for education. Applicants may be better served by interactive college guides that let students search according to lifestyle and learning preferences. Nobody wants to walk into Walmart and pay top-shelf prices for store-brand merchandise.

Frederick M. Hess is the director of education policy studies at the American Enterprise Institute, where Taryn Hochleitner is a researcher.