I am surprised at how narrowly utilitarian and instrumental (i.e. viewing college as a means to an end) all the answers have been so far. I am also willing to bet that a lot of people urging the drop-out path on kids are doing so with a degree or two under their belts. To point to the Black Swan dropouts like Bill Gates is about as sensible as pointing to the jackpot winners on slot machines in Vegas as aspirational examples.

I will leave aside the question of not-too-bright kids from bad K-12 tracks who need college educations merely to get functional in areas like communication and basic math. I will also ignore the case of kids from such narrow environments that college becomes their path from sub-human to human.

Let's talk about smart kids from decently-privileged backgrounds. The ones who can basically afford college without needing it to have an ROI because their parents are going to pay for all/most of it. To make this an even tighter best-case scenario, let's ignore the trustafarians coasting through college with a sense of entitlement and no intention or interest in transforming themselves in any way.

So we are talking about the cream of the 18-year-old cohort at any given time. The human potential that has the best chance of doing great things. Should a member of this high-quality set quit college for YC type stuff? (I am interpreting "chance to work with a YC/Techstars alum" broadly as "opportunity to dive into the startup world.")

There are two ways to view a college education. One is as an investment with a certain ROI and a risk profile around that ROI. Historically it's been a few percentage points increase in lifetime income per year beyond high school. Recently this has been dropping, and college is becoming less of a sure bet. This is really the only way to view vocational education. Things like nursing or auto-repair.

The other way to view it is as a mind-expanding experience. The "liberal" in liberal education (which includes the sciences and engineering), as opposed to vocational training is that in theory it is supposed to widen your horizons, show you things about yourself and the world, and introduce you to things that you would probably never run into if you didn't go to college.

The first kind of value is measurable and comparable with substitutes like YC, around very narrow areas like programming or graphic design. But believe it or not, there ARE other worthwhile things to do with your life than those. The entire point of the liberal education is to SHOW you those things so that you can choose from a broader set of options than the few that catch your fancy straight out of high school.

The second kind of value, when it works, is not measurable. Applying ROI thinking to it is about as meaningful as applying ROI thinking to the Mars rover. It is the sort of thing that helps make life more worth living. It is the sort of thing that can make you a better, more thoughtful person. Sure, many autodidacts think they can get the experience by reading up libraries of books, but they are sadly mistaken, because the value is delivered through dialogue, exams and relationships, at an age when your mind is both ready enough and empty enough to maximally benefit. When I meet such autodidacts (and not trying to be snobby here) I am struck by the strange sort of blindness to the social nature of knowledge they exhibit. They make very obvious and beginner mistakes in their handling of knowledge that college corrects early on.

But why pay good money for something with low (possibly negative) ROI like art history, philosophy, number theory or even some kinds of apparently "professional" degrees like engineering?

Because, if you can afford it, you get something more precious than money. This is why liberal education was the privilege of princes and priests in the days of slavery. Vocational education was for those who needed to worry about money. If you didn't need to do that, you could seek things beyond money.

If you cannot afford it (or can't wangle a scholarship), then certainly, money must come first. But if you can afford it, finish college. There is almost no better way to cash out a privileged background. It may soon be the case that liberal education is again only affordable for the super-rich. Get it while the gettin' is good.

For a narrow subset of students who catch startup fever/programming fever early, quitting and going YC will be the right decision. For the rest, it will be a case of premature optimization being the root of all evil (that quote, ironically enough, is due to Donald Knuth, a computer scientist). We'll never know if we we lost the next Shakespeare to some moronic me-too location-based mobile check-in app.

For all its problems, the democratization of specifically liberal education has been a huge accomplishment of the American higher education sector in the twentieth century. Know what you are setting aside in your eagerness for the startup game. Recognize that you may never again have the leisure (or brain power) to study Shakespeare or Nietzsche with an able guide and smart peers, and that one day when you are tired and depressed in your mid-thirties, you are far more likely to find solace in Shakespeare than in money or nice cars. Even within the narrower world of computing and software, recognize that the cost of diving early into "real world, hands-on practical stuff" is that you may never get to dive into things that offer great philosophical nourishment, like Turing machines or NP-completeness theory, or graph theory.

This is not to say that American higher education does not have problems. There are tons of crappy universities and professors. The institution could be better structured. Maybe students could blend credit-work courses with work experiences more flexibly, over more years. But to pretend that even the most fantastic YC alum mentor (heck, even a chance to have Steve Jobs as your mentor) can compare with the mind-exploding experience that is an education in a good university around people who have devoted their lives to learning and knowledge... that's just plain silly.

I often criticize higher education myself, very severely. I also like to give myself way too much credit for the good things about myself. But I'd be lying outright if I claimed that my 3 degrees (yeah, I went terminal) weren't pretty much a rebirth.I learned a lot from my startup/entrepreneurial experiences, but college was in a different league.

Addendum: I suppose I should mention this -- I faced this decision personally, though not at a basic college level. I took a year off from my PhD to be the first employee of a startup. They really wanted me to stay, and offered me a great deal, but I went back to finish my PhD. The company is now big and thriving, and I suppose if I'd stayed and not screwed up, I'd have done well. But it's a complete no-brainer to me that I chose the right option.