@inbook{NBERc10694,
 Crossref = "NBERgrub01-1",
 title = "Dropout and Enrollment Trends in the Postwar Period: What Went Wrong in the 1970s?",
 author = "David Card and Thomas Lemieux",
 BookTitle = "Risky Behavior among Youths: An Economic Analysis",
 Publisher = "University of Chicago Press",
 pages = "439-482",
 year = "2001",
 month = "January",
 URL = "http://www.nber.org/chapters/c10694",
}
@book{NBERgrub01-1,
 title = "Risky Behavior among Youths: An Economic Analysis",
 author = "Jonathan Gruber",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "2001",
 URL = "http://www.nber.org/books/grub01-1",
}