In Rational Exuberance: Silencing the Enemies of Growth and Why the Future Is Better Than You Think (HarperBusiness, 2004), Michael J. Mandel argues that the U.S. economy will not create enough jobs or wealth in the future unless breakthrough innovations--on the order of the Internet--take place. It is often assumed that vibrant, technology-driven growth, termed by Mandel as "exuberant growth," is the result of discoveries that seem at times random and haphazard. Are they? Mandel thinks not and argues that public policy can play a significant role in stimulating the development of new technologies. The author identifies these policies in his new book and contrasts them to those recommended by others.