I think they should!!!!! If it is something they really want to do.. I am 13 and NOT old enough to get a job.. I wish .. But every year I get together with my friends and go trick or treating... Alot of teens feel uncomfortable doing it because they want to be Popular..
I think it should be more for the little kids. Teens are old enough that they can earn money to buy their own candy instead of going around expecting hand-outs at every door. That said, I get really annoyed when a teen can't even be bothered to come up with a costume, or think it's enough to put on their regular sports outfit and say their costume is "football player" or whatever. Those kids have to tell me a clean joke to "pay" for their candy. The ones who have clever costumes get a bonus piece though.