[meric]

I meant, if you're invited to a high school to talk about raising your employment prospects, it is good idea to tell students to work hard and do well.

There are definitely people who would be better off dropping out as early as possible and start working but that's a minority.

Even electricians and mechanics require tertiary education. (Otherwise, what does my brother training to be a mechanic mean when he says he's going to "class"?!)

Dropping education as early as possible might be a good idea if your aim is to work in a field where knowledge can be easily self taught. (Like IT or painting). Even then, a one year crash course I think would be quite helpful. I self-taught myself programming too, but I only learned about "unit-testing" in university. I guess you can argue I could learn that in my first job, but what if I want to, say, do a startup? ;)

>> I really believe there is a correlation/causation problem with the "Higher educations leads to Higher Income"

We're talking about higher education leads to higher chance of being employed.