@techreport{NBERw12289,
 title = "Sources of Advantageous Selection: Evidence from the Medigap Insurance Market",
 author = "Hanming Fang and Michael P. Keane and Dan Silverman",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "12289",
 year = "2006",
 month = "June",
 URL = "http://www.nber.org/papers/w12289",
}