Malcolm Gladwell meets John Kenneth Galbraith. This book is a great read. However, the last third is pure "decision markets", so read along carefully. Why do we need more shortsellers? What do kids guessing the number of marbles in a jar and farmers guessing the weight of a steer have in common with stock market pricing? Why does a diverse group of holiday sailors make a better estimate of the trajectory of a missing submarine than a slate of experts? How do crowds move the line in sports betting, and why are they uncannily correct?