In the video below, Harvard University economist Edward Glaeser discusses his new book, "Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Greener, Healthier, and Happier." Glaeser, who  studies the economics of cities, segregation, crime and innovation, shatters the bad rap cities often get and suggests they are the healthiest, greenest and richest -- in cultural and economic terms -- places to live.