New goods are at the heart of economic progress. The eleven essays in this volume include historical treatments of new goods and their diffusion; practical exercises in measurement addressed to recent and ongoing innovations; and real-world methods of devising quantitative adjustments for quality change. The lead article in Part I contains a striking analysis of the history of light over two millennia. Other essays in Part I develop new price indexes for automobiles back to 1906; trace the role of the air conditioner in the development of the American south; and treat the germ theory of disease as an economic innovation. In Part II essays measure the economic impact of more recent innovations, including anti-ulcer drugs, new breakfast cereals, and computers. Part III explores methods and defects in the treatment of quality change in the official price data of the United States, Canada, and Japan. This pathbreaking volume will interest anyone who studies economic growth, productivity, and the American standard of living.