The Economy: Economics for a Changing World offers a fresh approach that integrates recent developments in economics including contract theory, strategic interaction, behavioral economics, and financial instability. This text challenges students to address complex issues such as inequality, climate change, economic instability, wealth creation, and innovation. It provides a unified treatment of micro- and macroeconomics, supporting all models and concepts with evidence and real-world applications. The book adapts to students’ own learning styles through interactive model building and serves as the standard for the Economic principles course at University College London, Sciences Po Paris, and the Toulouse School of Economics. A new economics for the principles course.