12 These benefits have traditionally been funded on a  8  See, for example, Henry M. Levin, Clive Belfield, Peter Muennig, Cecilia Rouse, Barbara Wolfe, and Nathan Tefft (2007), “The Public Returns to Public Educational Investments in African American Males”, Discussion Paper 112 (Minneapolis: Early Childhood Research Collaborative, April), available at www.earlychildhoodrc.org/papers/dp112-abstract.cfm.
9  See Alicia H. Munnell, Richard W. Kopcke, Jean-Pierre Aubry, and Laura Quinby (2010), Valuing Liabilities in State and Local Plans (Chestnut Hill, Mass. : Center for Retirement Research at Boston College, June). 10  See Joshua Rauh (2010), “Are State Public Pensions Sustainable?