This is an excellent way to explain socialism to your children. But the idea of 'Trick or Treat' itself is a 'spread the wealth' concept (kids going around asking strangers for free stuff). It's no wonder Halloween is the left's favorite holiday, outside of May Day. :)
No, it's like good old-fashioned charity. They are asking for something, there's no guarantee they'll get it. Now, if the children pointed AK47's at you while holding their little plastic pumpkins out for a Snickers,
that would be socialism.
;-)