In this revised and updated edition, the authors argue that there are several theoretical perspectives, each offering a plausible logical explanation to economic phenomena. The three theories discussed are: subjective preference theory; cost-of-production theory; and abstract labour theory. The theories are subject to non-mathematical analysis, and the authors show the links between economic theory and political practice for each. The book aims to provide a broad understanding of a wide range of economic theory and new material has been added, including the economic experiences of Chile and the global economic situation. Flow diagrams illustrate the text, and notes on further reading give additional guidance.