@techreport{NBERw10466,
 title = "Social Security and the Evolution of Elderly Poverty",
 author = "Gary V. Engelhardt and Jonathan Gruber",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "10466",
 year = "2004",
 month = "May",
 URL = "http://www.nber.org/papers/w10466",
}