Leon, José Gómez De; Keyfitz, Nathan - In: Population (french edition) 35 (1980) 04-mai, pp. 815-836
Keyfitz Nathan and Gómez de Leon José. ? Demographic Considerations on Pension-Systems. As populations in developed countries age, the burden of pay-as-you-go pensions is increasing and consideration is again being given to a system of funding, where contributions do not depend on the age...