@techreport{NBERw11182,
 title = "Cohort Turnover and Productivity: The July Phenomenon in Teaching Hospitals",
 author = "Robert S. Huckman and Jason Barro",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "11182",
 year = "2005",
 month = "March",
 URL = "http://www.nber.org/papers/w11182",
}