@inbook{NBERc7912,
 Crossref = "NBERfree88-1",
 title = "On Estimating the Effects of Increased Aid to Education",
 author = "Ronald G. Ehrenberg and Richard Chaykowski",
 BookTitle = "When Public Sector Workers Unionize",
 Publisher = "University of Chicago Press",
 pages = "245-270",
 year = "1988",
 URL = "http://www.nber.org/chapters/c7912",
}
@book{NBERfree88-1,
 title = "When Public Sector Workers Unionize",
 author = "Richard B. Freeman and Casey Ichniowski",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "1988",
 URL = "http://www.nber.org/books/free88-1",
}