I just read about this in a book Freakonomics by Steven D. Levitt and Stephen J. Dubner. I was amazed how well the Superman stories worked. Freakonomics: http

I just read about this in a book Freakonomics by Steven D. Levitt and Stephen J. Dubner. I was amazed how well the Superman stories worked. Freakonomics: https://en.wikipedia.org/wiki/Freakonomics https://en.wikipedia.org/wiki/Freakonomics