A while ago I read The Upside of Irrationality by Dan Ariely and really liked it. The way it was written was direct, evidence-based, and humorous, and so I wanted to check out Ariely's latest book, The Honest Truth about Dishonesty: How We Lie to Everyone--Especially Ourselves. This one I thoroughly enjoyed as well.
The main point of the book was that scientific experiments have shown that almost all people lie and cheat by a small amount (10-15%) at every opportunity they get, and the "simple model of rational crime" (with people weighing expected benefits against expected costs) totally doesn't hold in real life. The most interesting thing, though, is how people even deceive themselves so they can maintain their identity and self-image as moral and honest.
While the book was mainly describing behaviors as a result of different stimuli, it did talk about some prescriptions that do seem to help counteract cheating, such as giving reminders right at the point of temptation and actual supervision.
According to the book, here is a summary of forces that shape dishonesty (clearly, there are so many more forces that tend to increase dishonesty):