In Public Goods, Public Gains, Link and Scott discuss the systematic application of alternative evaluation methods to estimate the social benefits of publicly-financed research and development (R&D). The authors argue that economic theory should be the guiding criterion for any method of program evaluation because it focuses attention on the value and the opportunity costs of the program. The evaluation methods discussed and illustrated are both economics and, for comparison, non-economics based. The book is motivated by four foundation chapters that discuss government's role in innovation from the perspective of economic theory, review public accountability issues from both a constitutional and an historical perspective, overview systematic approaches to program evaluation, and describe the evaluation metrics typically used. Four case studies illustrate the four alternative evaluation approached discussed. These case studies are for the U.S. Advanced Technology Program's intramural research awards program, the U.S. National Institute of Standards and Technology's research on wavelength references for optical fiber communications, the U.S. Malcolm Balridge National Quality Award, and the Advanced Technology Program's focused program on the integration of manufacturing applications. Public support of R&D has played a vital role in U.S. economic growth but, at the same time, there is always the danger of wasting money by supporting bad projects. Link and Scott are two of the premier economists in the field, and in their superb book they lay out the approach needed to decide if and how public support should be provided. Globally, there is increasing public support for R&D and the U.S. should respond to the competitive pressure, but only by doing it right. Link and Scott tell us how.