Blending common phenomena and subtle experiments with groundbreaking analyses, Ariely shows how expectations, emotions, social norms and seemingly irrational forces of the unseen are distorting our reasoning skills. It would be dangerous for us to rely on conventional economics theories when planning personal, national and global policies. Mistakes we make as individual or institutional are never random, and when they come together, they can create an impact on the market with destructive consequences. The results of these systematic and predictable errors are explained for the first time under the light of the current global economic crisis.