After peaking in 2011 at 20.6 million, college enrollments in the United States have declined every year since, falling to 19 million in 2016. While the fall-off has been most pronounced in community colleges and for-profit institutions, many traditional four-year institutions have been affected as well.

Why, ask Richard Vedder and Justin Strehle, is this happening? Because the cost of college attendance is rising while the financial benefits of a degree are falling, they argue in a Wall Street Journal op-ed.

Between 2000 and 2016, the tuition-and-fees component of the Consumer Price Index rose 74.5%, adjusted for overall inflation. But the earnings advantage of a college degree is no longer growing like it once did. Writer Vedder and Strehle:

The average annual earnings differential between high school and four-year college graduates rose sharply, to $32,900 in 2000 (expressed in 2015 dollars) from $19,776 in 1975 — only to fall to $29,867 by 2015. In the late 20th century rising higher-education costs were offset by the increasing financial benefits associated with a bachelor’s degree. Since 2000 those benefits have declined, while costs have continued to rise.

An indicator of this shifting return on investment is the high rate of underemployment — 40%, according to Vedder and Strehle — of recent college graduates. When college grads are taking jobs as Uber drivers and baristas, you know something is wrong.

Another factor undermining the advantage of a college degree: A degree no long provides the reliable signaling to the labor market that it once did. Traditionally, a sheepskin used to tell employers that a candidate possessed a certain level of intelligence, ambition and diligence. But when one third or more of adult Americans graduate from college, “being a college graduate no longer necessarily denotes exceptional vocational promise,” the authors write.

Bacon’s bottom line: There is a deeply rooted idea in American culture that everyone should have a chance to go to college. Embedded in that idea is the assumption that everyone can benefit from a college education. In an ideal world that might be true. But we live in the world we live in, and the K-12 educational pipeline is badly broken. High schools are spewing out graduates who are totally unprepared for college-level work. But many colleges, desperate to maintain their enrollments and support the vast infrastructure of buildings, departments, faculty, graduate students and administrators, are taking on these students anyway, even if they benefit little from the college experience. Here in Virginia, thousands of students drop out every year after loading up with college debt. Even for those who do graduate, thanks to relaxed academic standards, a college degree in many cases ain’t worth what it used to be.

Since the Top Jobs Act of 2011, in which it was the declared policy of Virginia to increase the number of degrees and certificates awarded by Virginia’s public colleges and universities by 100,000, enrollments have plateaued after years of increases. Virginia students are encountering the same hard choices as students nationally: Given what Virginia institutions are charging, is the cost of a degree really worth it?