Raj Chetty is the William A. Ackman Professor of Economics at Harvard University, director of Opportunity Insights, and a research associate and director of the Public Economics Program at the National Bureau of Economic Research. John N. Friedman is professor of economics and international and political affairs at Brown University and a research associate of the National Bureau of Economic Research. Janet C. Gornick is professor of political science and sociology, director of the Stone Center on Socio-Economic Inequality, and holds the James M. and Cathleen D. Stone Distinguished Chair in Socio-Economic Inequality at the City University of New York. Barry Johnson is deputy chief data and analytics officer and director of the Statistics of Income Division at the Internal Revenue Service. Arthur Kennickell is a Stone Center Affiliated Scholar at the City University of New York and a member of the board of directors of the National Bureau of Economic Research.