It is an amazing but little-remarked fact that governments all over the world take as their top economic objective the increase of one number: gross domestic product. Philipp Lepenies traces how this strange unanimity came to be, taking the reader on a colorful journey through England, Germany, and the United States and bringing things into the present with an account of current debates about replacing or supplementing GDP with other indicators of welfare. The Power of a Single Number is beautifully written and easily accessible to anyone who wants to know more about what lies behind the world's most powerful number. -- Robert H. Wade, London School of Economics. Leontief Prize winner, 2008. A great book on understanding why GDP was put at the center of the political and economic framework that has driven the world over the past sixty years and why this choice led to the underestimating of other issues, such as socioeconomic inequalities and environmental degradation. The Power of a Single Number also provides insights on how to build a 'post GDP' era, especially in the context of a possible future 'secular stagnation.' -- Enrico Giovannini, University of Rome By asking how GDP became the most influential economic statistic of our time, Lepenies provides a fascinating new perspective on the history of empirical economics. Economists play important roles in his account, but ultimately it was politics and the priorities of wartime that drove the demand for GDP measurement. While many economists today are well aware of its limitations, political inertia keeps GDP on its throne. -- Martin Ravallion, Georgetown University This little book about a big number will impress readers who might never have previously considered the statistics underlying our lives. Publishers Weekly Lepenies's absorbing account helps us understand the personalities and popular events that propelled GDP to dominance, clarifying current debates over the wisdom of the number's rule. 800-CEO-READ