There's an article by Walter Kirn, Lost In The Meritocracy, back from '05 and which later became a book, that pretty much sums up what's going on with higher education in this country, and what's wrong with the American economy in general. It's that college, our engine of income mobility, isn't.
If you read the article, it makes the cause of the twelve-fold increase in the cost of college in the last thirty years apparent. It's the same thing that's going on in Meritocracy when roommates demand five hundred unaffordable bucks for unasked for improvements. This debate could've been avoided by jacking up the tuition and having the cost of perks paid for by the college, and that's exactly what's been happening. Colleges have chosen to move "up-market", and away from the American people.
Despite massive increases in demand, Princeton, Harvard, Yale, the Ivy Leagues have barely increased enrollment. Part of this is that elite colleges aren't as much in the business of educating, as in creating useful connections. Partly those it pays to be connected to are those with the most ability to make things, and partly those who already have things.
There all sorts of debates about the values of a liberal education. There's the idea that it increases our virtues as citizens. I'm skeptical of the art of being an American is something that can be taught. Even more so of the idea that isn't something held more by upper Manhattan professor than a West Virginia coal miner.
As to claims it increases a student's income compared to other Americans, I can't help wondering if that isn't what we should be trying to fix.