@techreport{NBERw12019,
 title = "Ugly Criminals",
 author = "Naci Mocan and Erdal Tekin",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "12019",
 year = "2006",
 month = "February",
 URL = "http://www.nber.org/papers/w12019",
}