Drawing on a lifetime of distinguished work in economic research and policymaking, Andrew Kamarck details how his profession can more usefully analyze and solve economic problems by changing its basic approach to research. Kamarck contends that most economists today strive for a mathematical precision in their work that neither stems from nor leads to an accurate view of economic reality. He develops elegant critiques of key areas of economic analysis based on appreciation of scientific method and knowledge of the limitations of economic data. Concepts such as employment, market, and money supply must be seen as loose, not exact. Measurement of national income becomes highly problematic when taking into account such factors as the so-called underground economy and currency differences. World trade analysis is based on inconsistent and often inaccurate measurements. Subtle realities of the individual, social, and political worlds render largely ineffective both large-scale macroeconomics models and micro models of the consumer and the firm. Fashionable cost-benefit analysis must be recognized as inherently imprecise. Capital and investment in developing countries tend to be measured in easy but irrelevant ways. Kamarck concludes with a call for economists to involve themselves in data collection, to insist on more accurate and reliable data sources, to do analysis within the context of experience, and to take a realistic, incremental approach to policymaking. Kamarck's concerns are shared by many economists, and his eloquent presentation will be essential reading for his colleagues and for those who make use of economic research.