Sebastian Mallaby based this book on 5 years of untrammelled access to Greenspan, plus all papers associates and intimates from 2010 to 2015. The writer is Senior Fellow for International Economics at the Council on Foreign Relations, a staff writer for the Economist, and has been a columnist for the Washington Post and Financial Times.  This book won the FT & McKinsey Business Book of the Year 2016.  Not only about money, this book also covers his complicated relationships with Barbara Walters and the other women in his life (many). It asks the central questions: why did a man so universally celebrated forge a financial system that proved so unstable?  How will his successors protect us from a future crash. A book that treats its subject intelligently and humanely.