This book, which was first published in 1972, is not a collection of case-studies in cost-benefit analysis, of which there had been already several in use employing techniques of varying degrees of sophistication. Nor is it a manual of instruction with particular orientation for less developed counties, such as those produced under the auspices of the U.N. and the O.E.C.D. What this volume does attempt is to introduce the student of economics to the logic and the concepts used in cost-benefit analysis.