This edition represents our efforts to continue refining and modernizing our treatment of microeconomic theory. Despite the significant change appearing in virtually every chapter, the text retains all of the elements that have made it successful for? so many editions. The basic approach is mathematical tools needed to go further in their studies. The text also seeks t facilitate that linkage by providing many numerical example, advanced problems, and extended discussions of empirical implementation-all of which are intended to show students how microeconomic theory is used to today.