1. Auerbach AJ, Lee R (2011) Welfare and generational equity in sustainable unfunded pension systems. J Public Econ 95(1):16–27
2. Blanchard O, Chouraqui JC, Hagemann RP, Sartor N (1990) The sustainability of fiscal policy: new answers to an old question. OECD Econ Stud 15:7–36
3. Borgmann CH (2005) Social security, demographics, and risk. Population Economics. Springer Science & Business Media. Springer Berlin Heidelberg
4. Börsch-Supan A (2006) What are NDC systems? What do they bring to reform strategies? Pension reform: Issues and prospects for non-financial defined contribution (NDC) schemes, 35–55
5. Boskin M, Shoven J (2009) Concept and measures of earnings replacement rates during retirement. In: Bodie Z, Shoven J, Wise D (eds) Pensions and retirement in the United States. NBER, University of Chicago Press, Chicago, pp 113–141