[Handbook of Public Economics] Volume 3 || Tax Avoidance, Evasion, and Administration**We are grateful to Wojciech Kopczuk for valuable research assistance. Helpful comments on an earlier draft were received from Jim Alm, Alan Auerbach, Len Burman, Brian Erard, Martin Feldstein, Firouz Gahvari, Roger Gordon, Jim Hines, Jonathan Kesselman, Louis Kaplow, Jim Poterba, Agnar Sandmo, Dan Shaviro, Eric Toder, Gideon Yaniv, the participants at the NYU Law School Colloquium on Tax Policy and Public Finance and the handbook conference held at the University of California at Berkeley.