'Richard Ruggles, often assisted by Nancy Ruggles, has been a major contributor to national income accounting and to the empirical study of microeconomics and macroeconomics using that and other data. He has focused on the quantitative analysis of actual economic systems in a discipline increasingly preoccupied with abstract pure conceptual models. Like the work of Simon Kuznets and others, Ruggles's analyses encompass an unusually wide range of variables.' - Warren J. Samuels, Michigan State University, US This volume reflects the pioneering contribution of Nancy and Richard Ruggles to the development of national accounts. It provides a comprehensive overview of the evolution of national accounting systems over the last 50 years.