ARTHUR O'SULLIVAN is a professor of Economics at Lewis and Clark College in Portland, Oregon. After receiving his B.S. degree in economics from the University of Oregon, he spent two years in the Peace Corps, working with city planners in the Philippines. He received his Ph.D. degree in economics from Princeton University in 1981 and taught at the University of California, Davis, and Oregon State University, winning teaching awards at both schools. He is the Robert B. Pamplin Junior Professor of Economics at Lewis and Clark College in Portland, Oregon, where he teaches microeconomics and urban economics. He is the coauthor of the introductory textbook, Economics: Principles and Tools, currently in its eighth edition. Professor O'Sullivan's research explores economic issues concerning urban land use, environmental protection, and public policy. His articles appear in many economics journals, including Journal of Urban Economics, Regional Science and Urban Economics, Journal of Environmental Economics and Management, National Tax Journal, Journal of Public Economics, and Journal of Law and Economics.