In this book, Charles Mackay discusses the irrational behaviors of crowds in the economy, war and magic. He gives several different examples of market bubbles such as the Mississippi Scheme and the infamous Tulip Mania in the Netherlands. Ever since it was written, Investors have used it as a guide to help identify boom and bust cycles. Extraordinary Popular Delusions and The Madness of Crowds has had an important influence on economists in understanding of crowd psychology and feedback loops.