标题1：The Aging Population and the Size of the Welfare State
作者：Assaf Razin
期刊：Journal of Political Economy, 2002, vol. 110, no. 4
链接：http://www.journals.uchicago.edu/doi/abs/10.1086/340780
标题2：Developments in the prediction of effective population size
作者：Richard Disney
期刊：European Journal of Political Economy Volume 23, Issue 2, June 2007, Pages 542-553
链接：http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V97-4JVTC2C-1&_user=7104648&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1038028440&_rerunOrigin=scholar.google&_acct=C000071115&_version=1&_urlVersion=0&_userid=7104648&md5=7810e533d41feef8038897910b4c55d3
标题3：Stochastic population forecasts for the United States: beyond high, medium, and low
作者： RD Lee, S Tuljapurkar -
期刊： Journal of the American Statistical Association, 1994 - questia.com
链接：http://www.questia.com/googleScholar.qst?docId=5002221954