Economics. I've just figured it ALL out. From one very insightful paragraph

[Honeycombe8]

15. We don't apply for what we "want." We apply for what we can do.

More people can do the duties of a janitor than those of a teacher. Being a teacher requires a degree and licensing. You just need to have physical ability to become a janitor.

If you run an ad for a janitor position, a lot more people will apply, because a lot more people qualify to do the job, than for a teaching position.

If the job has few requirements that most people can't meet, and if it's something that a lot of people can do, that job will not pay much. That's because it doesn't have to. If you own a business and can hire a janitor for $6.00 an hour, you will probably not hire someone to do the job for $12.00, all things being equal as to what you need. It doesn't make sense.

That's why Tom Cruise gets paid millions per movie, while Bernie Smith gets acting union wages. Only one person in the world can do what Tom Cruise does. If that's what you need, you have to outbid others to get him.

Life lesson #45: If you want to get paid more, choose a vocation/profession that requires something that most people won't have (or don't want to do), and which is perceived as necessary and valued. An emphasis in a field that is male dominated is helpful, since those fields tend to pay more. (engineering, surgery, dentistry, etc.)

But most people, like myself, just fall into a vocation, esp if they aren't raised to consider this very important thing while they're growing up.