20-Year Prospect
Hang on. This is supposed to be Mrs. Rodriguez's class. Who's this weird guy calling himself Mr. Anderson? We don't like Mr. Anderson. We must torment Mr. Anderson.
Well, that was how we used to think, back when we were but wee Shmooplings. Now we look at substitute teachers the way we should: as the thin line between order and anarchy in the classroom. The question is: will other generations have the same kinds of experience we will?
All signs point to yes. As the demand for teachers increases, so does the demand for substitute teachers when the others get sick. Substitute teachers are looking at a seventeen percent growth rate over the next ten years, which really isn't bad at all (source).
There's even a shortage of qualified substitutes, which may have something to do with the unreliable hours, low pay, and the occasional bully (kids can be mean) (source). Unsurprisingly, the job outlook is best for those in the most populous states. The more people there are, the more kids need to be taught.
The biggest danger to the position lies in the prevalence of computers. There won't be robotic teachers, but the idea of a single teacher reaching multiple classrooms via computers isn't far-fetched. We're still not sure how discipline might work when that happens.
Chances are, being a substitute teacher for life isn't your end goal. You either want to support some other endeavor—like your band or your line of artisanal cheeses—or you're looking to actually become a full teacher. You're not going to be doing this in twenty years.
With any luck you'll have your own students tormenting someone else whenever you have a head cold. But in twenty years, if you end up needing to go back to subbing, it'll probably be there.