Principles of Economics is a comprehensive textbook for undergraduate and postgraduate students. The book begins with a simple introduction to economics as a social science, moves on to basic economic problems of individuals, firms and the society focusing on the problem of scarcity and choice, and finally discusses the higher levels of economic theories. While the basic principles of economics remain the same as delineated in the first edition, the need for bringing out the second edition is three-fold. First, “Principles of Economics” is being reintroduced in the economics syllabi of various universities with an increasing emphasis on macroeconomics and international economics. This new trend has enhanced the relevance and usefulness of this book. Secondly, there is a greater emphasis on quantitative method of elaboration and exposition of economic theories rather than high-level mathematics. So there was a need to introduce simple quantitative methods in the presentation of theories. Thirdly, the application of economic concepts and theories to real life problems is also being focused on which is also finding entry into management, medical and engineering courses. So application content has been brought into focus in this second edition. Thus substantial changes have been made for this edition, most chapters have been rewritten, expanded and updated while some new chapters have been added. Graphical illustrations and simple algebraic formulations have been used, wherever necessary, for clear exposition of economic theories. Review questions and exercises are given at the end of each chapter to help students assess their own understanding of economics. Principles of Economics will be of immense value to students of economics, BBA, MBA, and those preparing for professional and competitive examinations such as IAS, IES, CA, ICWA and CS. Students of engineering and medical courses who have virtually no prior subject knowledge and have to clear an economics paper will find this book a boon.