@inbook{NBERc0168,
 Crossref = "NBERpote05-1",
 title = "Introduction to "Tax Policy and the Economy, Volume 19"",
 author = "James M. Poterba",
 BookTitle = "Tax Policy and the Economy, Volume 19",
 Publisher = "MIT Press",
 year = "2005",
 month = "September",
 URL = "http://www.nber.org/chapters/c0168",
}
@book{NBERpote05-1,
 title = "Tax Policy and the Economy, Volume 19",
 author = "James Poterba",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "MIT Press",
 year = "2005",
 URL = "http://www.nber.org/books/pote05-1",
}