Tax Policy and the Economy, Volume 15 2001 HKS Authors See citation below for complete author information. Jeffrey Liebman Director of the Taubman Center for State and Local Government Robert W. Scrivner Professor of Social Policy David Ellwood Isabelle and Scott Black Research Professor of Political Economy, Emeritus Citation Ellwood, David, and Jeffrey Liebman. "The Middle Class Parent Penalty: Child Benefits in the U.S. Tax Code." Tax Policy and the Economy, Volume 15. Ed. James M. Poterba. MIT Press, 2001.