The Great Depression of the 1930s gave birth to a branch of economics that in 1933 Ragnar Frisch christened macroeconomics. Over the decades that followed up to the present, the interactions of economic events, economic policy, and macroeconomic theory have created a fascinating story integral to the life and politics of national economies around the world. This book recounts that story. It brings together three strands of activities and trends: the economic events of the twentieth and twenty-first centuries that defined the economic problems facing the nation, policymakers, and economists; the responses of economists who brought the accumulated knowledge of the profession to bear on these problems; and the successes and failures of these policies as they reshaped the economic landscape and defined new sets of problems to be analyzed by macroeconomic theory. This highly readable book presents an unconventional perspective on macroeconomics the interplay of theory and policy in a historical context.