The book introduces what we call a "Three-Dimensional" approach to economics. Competition and choice through market interactions. Exercise and exercise of power in markets, within businesses, and in society as a whole. Change in the economic institutions that govern economic life, examined both from a theoretical and historical perspective, as an evolving process. It is divided into 4 parts: a) Competition, Command, and Change b) Capitalism and classes c) Microeconomics: markets and power d) Macroeconomics: unemployment and economic growth. The book is an introduction to the subjects of Microeconomics and Macroeconomics, but can also be used as a supplement or as a text for debate in courses that use neoclassical methods in economics or in series of interdisciplinary courses in social classes.