This work discusses the application of theoretical methods to economic development. The authors break their analysis into distinct sections--macroeconomics, industrial organization, planning and public policy, and intertemporal economics. In each section, they approach specific issues with a rigorous analysis, from the influence of Kalecki in macroeconomics to the design of a decentralized planning procedure to decide on resource allocation between public and private sectors. They also examine fundamental issues underlying well-known models of intertemporal behavior, both inter- and intragenerational. Discussing complex theories clearly related to problems of development, this work will interest students and scholars of development economics, and professionals involved in policy, economic research, and planning.