You are hereby fined 10 internets for referencing Seinfeld and then failing to specify a knife and fork for the eating of candy bars.
Please pay at the next Information Superhighway toll booth.
The York Peppermint Patties I bought this year for trick-or-treaters were definitely smaller in size than the ones I bought last year. No idea how much.
An equally interesting question would be how much have the contents changed over the years? If you ate a Hershey’s bar from 1913, would it taste anything like the 2013 version?
Probably dry and dusty. 
Stephen Jay Gould wrote an essay on the changing sizes of Hershey bars. Let’s see if Google… yup:
from here: Rising Cost of Candy - A Brief Study of Hershey Prices - Candy Blog
The article also has a nice chart showing the price AND size of the basic Hershey bar from 1908 to 2008.
Dr. David “Reese” Banner: Please don’t make me angry, Mr. McGee. You wouldn’t like me when I’m angry.
Jack “Czarcasm” McGee (tying on a paper bib): Yeah, no; I kinda think you’re wrong there…