This book discusses the total effects of the project on incomes and the net demands for goods and services in the economy. The differences between the total effects and the direct effects, the theme of this book, are usually called the project's indirect or downstream effects. The downstream effects of a private project are of no interest to the entrepreneur who undertakes it; but when such effects arise from a project in the public sector, they should be of keen interest to the people who evaluate and finance such projects. There are a number of obvious questions: How large are the downstream effects and who reaps the benefits or losses? Will they be concentrated largely in the immediate geographical region in which the project is located? What will be their impact on government revenues? These are not new questions. Yet there have not been many attempts to provide quantitative estimates of the downstream effects of particular projects. Thus, although this book places a strong emphasis on methods, it is based on a case study of a project that was completed in the mid-1970s, the Muda Irrigation Project.