From a clever Consumerology blog post about the economics of halloween:

It seems to me that trick-or-treating is the first job that most of us have. Sure, it’s only one day a year, but kids put forth the effort to get dressed, make the commute, and cold call perfect strangers. They get paid (in candy or, cruelly, all manners of non-candy including fruit and pencils) and then experience the indignity of losing some of that income to “the man” – in this case, parents with the misguided notion that they deserve a piece of the action.