Life sometimes seems illogical. Individuals do strange things: take drugs, have unprotected sex, mug each other. Love seems irrational, and so does divorce. On a larger scale, life seems no fairer or easier to fathom: Why do some neighborhoods thrive and others become ghettos? Why is racism so persistent? Why is your idiot boss paid a fortune for sitting behind a mahogany altar? Thorny questions–and you might be surprised to hear the answers coming from an economist. But award-winning journalist...