Since August 2008, William A. Pizer has been the deputy assistant secretary for environment and energy. 

During 2001-2002, he served as a senior economist at the President's Council of Economic Advisers where he worked on environment and climate change issues. He was a visiting scholar at Stanford University's Center for Environmental Science and Policy during 2000-2001, and taught at the Johns Hopkins University during 1997-1999. Pizer's research seeks to quantify how various features of environmental policy and economic context, including uncertainty, individual and regional variation, technological change, irreversibility, spillovers, voluntary participation, and flexibility, influence a policy's efficacy.

Pizer holds a Ph.D. in economics from Harvard University and a B.A. in physics from the University of North Carolina.

• Climate Change Policy in the United States 2006 (April 19, 2006)