The free market isn’t merely the best mechanism ever devised to provide people with what they want; it is also the best mechanism ever devised to provide people with what they don’t want. That is the thesis of the new book “Phishing for Phools: The Economics of Manipulation and Deception,” by Nobel laureates in economics George A. Akerlof and Robert J. Shiller.

In their book, a business “phishes” when it exploits the informational and emotional weaknesses of customers in order to sell them goods, services or investments that...