Read the following excerpt from Levitt and Dubner’s Freakonomics. In the beginning, Feldman left behind an open basket for the cash, but too often the money vanished. Then he tried a coffee can with a money slot in its plastic lid, which also proved too tempting. In the end, he resorted to making small plywood boxes with a slot cut into the top. The wooden box has worked well. Each year he drops off about seven thousand boxes and loses, on average, just one to theft. This is an intriguing statistic: the same people who routinely steal more than 10 percent of his bagels almost never stoop to stealing his money box—a tribute to the nuanced social calculus of theft. From Feldman’s perspective, an office worker who eats a bagel without paying is committing a crime; the office worker probably doesn’t think so. This distinction probably has less to do with the admittedly small amount of money involved (Feldman’s bagels cost one dollar each, cream cheese included) than with the context of the “crime.” The same office worker who fails to pay for his bagel might also help himself to a long slurp of soda while filling a glass in a self-serve restaurant, but he is very unlikely to leave the restaurant without paying.

Which of the following best summarizes the main idea of this paragraph?