Stephen Colbert interviews economist Tim Harford about his then-recent book, Logic of Life. Harford and Colbert discuss a number of items that people may consider irrational, but actually turn out to be rational like voting, unprotected sex, and smoking. The entire discussion focuses on the central idea of the definition of rationality.
Charlie decides to start smoking in the mailroom because it’s a stressful job and the cigarettes help him calm down. He rationalizes it that it’s okay to do something so risky because he has health insurance. In economic terms, health insurance creates a moral hazard because Charlie is only smoking because he knows he has insurance and he wouldn’t be as risky without it.