His area of specialization is environmental and natural resource economics, and he has extensive experience in such timely issues as: air pollution and its effects on human health; water allocation in the southwestern United States; and the economics of recycling. He has worked on a variety of research projects, and as a consultant, for such organizations as: the American Lung Association; the South Coast Air Quality Management District; the Bay Area Air Quality Management District; the California Air Resources Board; the World Bank; and the cities of San Diego, California, and Houston, Texas.