Honour codes do work-- see Ariely's book on honesty: http://www.amazon.com/gp/product/0062183591?ie=UTF8&camp... (quote from blurb: Ariely argues, and then demonstrates, that it's actually the irrational forces that we don't take into account that often determine whether we behave ethically or not.)

Also, cheating on an exam is a classic tragedy of the commons-- if everyone did it, course grades are meaningless. And yes, this comment has rather misinformed views of "over there".