I don't think it's a guarantee. In the UK (where tuition is capped at £9k($12k)/year), a whole heap of majors were shown to reduce lifetime earnings vs not going to university.

The difficulty is that you are going to earn a lot less while you are at university, so if you spend 3 years there earning $0, it really drags down lifetime earnings unless the degree adds a somewhat decent %age above baseline in terms of earning power.

> The difficulty is that you are going to earn a lot less while you are at university, so if you spend 3 years there earning $0, it really drags down lifetime earnings unless the degree adds a somewhat decent %age above baseline in terms of earning power.

You'd have to have a less than 7% earning power increase, and I wouldn't even call that a decent percentage for one year of dedicated self-funded training.

>It's called free because it's "given without charge"

It's not given without charge, because the taxpayer was charged. If my friend buys my lunch because I left my wallet at home, or it was more expensive than I thought, I don't say "oh wow, free lunch!" I acknowledge that the lunch was paid for by someone else. I certainly wouldn't go around telling people I got free lunch that day. That's a surefire way to make sure nobody helps me out again.