Ridleyridley, Freedman and Zihan Models

Ridley, he's the author of the excellent book, the rational optimist, how prosperity evolves. The second model is a book that i read d guess a couple o years ago. It was called the storm before the calm. And a freedman model says, the 20 twenties in the united states and on a global basis. So we'll call that the freedman model, then the zihan model.