Why do heroes fight each other? Why do villains keep trying even though they almost never win? Why don't heroes simply take over the world? Economics and comic books seem to be a world apart. But in the hands of economics professor and comic hero aficionado J. Brian O'Roark, the two form a powerful alliance. With brilliant deadpan enthusiasm he shows how the travails of superheroes can explain the building blocks of economics, and how the laws of economics explain the mysteries of superhero behavior. Superman has a day job because of elastic demand; Spiderman's existential doubts are all about opportunity cost; game theory sheds light on the battle between Captain America and Iron Man; the Peltzmann effect makes sense of why heroes can go to the bad; sunk cost fallacy explains The Flash's tragic dilemmas; the utility curve helps us decide who is the greatest superhero of all. Why Superman Doesn't Take Over The World: What Superheroes Can Tell Us About Economics probes the motivations of our favorite heroes, and considers what it would look like if their stories played out in reality.