@techreport{NBERw12041,
 title = "Sorting in Experiments with Application to Social Preferences",
 author = "Edward Lazear and Ulrike Malmendier and Roberto Weber",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "12041",
 year = "2006",
 month = "February",
 URL = "http://www.nber.org/papers/w12041",
}