Institute for Social Research, Survey Research Center, University of Michigan, PO Box 1248, Ann Arbor, MI 48106, U.S.A.
Robert F. Schoeni
Institute for Social Research, Survey Research Center, University of Michigan, PO Box 1248, Ann Arbor, MI 48106, U.S.A.
Mick P. Couper
Department of Economics, 611 Tappan St., and Gerald R. Ford School of Public Policy, 735 S. State St., University of Michigan, Ann Arbor, MI 48109, U.S.A.