Are too many people going to college? I tend to think so -- and I've suggested that, rather than trying to prod more kids into higher education, we should focus on improving the situation for the ones who already go. Around 40 percent of them don't graduate in six years, and many of those who do graduate end up in jobs that don't even require a degree.

Today, Inside Higher Ed has a piece covering a new study about the "murky middle" -- college kids who aren't lost causes, but who are still at a substantial risk of not graduating. Here's a chart of freshman-year grades and six-year graduation rates:

Basically, by the end of their first year, more than a tenth of college students have shown they almost certainly don't have what it takes to graduate, earning a C average or less -- and fewer than half of students have at least a two-thirds chance of making it, which corresponds to an A to B average.

Remember, these kids are self-selected -- they're the ones who decide, based on their performance in high school and the incentives in front of them, that going to college is a good idea. If we change the incentives to push even more kids into college, those kids will be even worse off, on average.

Much better to see what we can do for that "murky middle."

Robert VerBruggen is editor of RealClearPolicy. Twitter: @RAVerBruggen