This 18-chapter text is the first book explicitly designed for the one-term, principles-level course covering both micro and macroeconomics, and can also be used for two-term or full-year courses where a very concise, focused treatment is desired. This authoritative text carefully selects and fully explains all of the core topics essential to the principles course with a rigorous and analytical treatment, rather than presenting just a cursory "survey" of all introductory economic concepts. It presents economics as a unified subject in which the macroeconomics chapters build on, and flow from, the key microeconomic principles established in the first half of the book.