@techreport{NBERt0337,
 title = "Regression Discontinuity Designs: A Guide to Practice",
 author = "Guido Imbens and Thomas Lemieux",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Technical Working Paper Series",
 number = "337",
 year = "2007",
 month = "April",
 URL = "http://www.nber.org/papers/t0337",
}