The proven concept of introducing problems through questions and answers has been retained in the fifth edition. This approach trains the reader in economic thinking and helps them learn not just pre-existing knowledge that they are likely to forget a few months after the exam. The unifying theme for this interdisciplinary introduction to microeconomics is the concept of opportunity cost—a way of thinking that connects psychology, sociology, political science, and law with economics. The book also includes the usual formal representation of households and firms. Additionally, it offers exercises ranging from the fundamentals of microeconomics to self-organization and evolution, including evolutionary games, oligopoly, consumer and producer surplus, the Shapley value, and chaos and catastrophe theory.