From Munger in The Psychology of Human Misjudgment: "And human nature, with its version of what I call incentive-caused bias, causes this terrible abuse. And many of the people who are doing it you would be glad to have married into your family compared to what you’re otherwise going to get. "Now there are huge implications from the fact that the human mind is put together this way, and that is that people who create things like cash registers, which make most behavior hard, are some of the effective saints of our civilization. And the cash register was a great moral instrument when it was created. And Patterson knew that, by the way. He had a little store, and the people were stealing him blind and never made any money, and people sold him a couple of cash registers and it went to profit immediately."