The U.S Federal Debt Outlook: Reading the Tea leaves by Oya Celasun and Geoffrey Keim. In this paper, they speaks that fiscal policies reflecting a primary balance response to higher debt in line with historic experience would significantly increase the likehood of reaching the debt targets of the U.S. administration in the medium term. Deficits and debt are higher under current budgetary proposals and IMF projections for real activitu and interest rates, which do not include a reaction of policies to rising primary deficits. see:
http://www.imf.org/external/pubs/cat/longres.cfm?sk=23692.0
