@inbook{NBERc11569,
 Crossref = "NBERsumm90-1",
 title = "Introduction, acknowledgments",
 author = "Lawrence H. Summers",
 BookTitle = "Tax Policy and the Economy: Volume 4",
 Publisher = "The MIT Press",
 year = "1990",
 month = "January",
 URL = "http://www.nber.org/chapters/c11569",
}
@book{NBERsumm90-1,
 title = "Tax Policy and the Economy: Volume 4",
 author = "Lawrence H. Summers",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "The MIT Press",
 year = "1990",
 URL = "http://www.nber.org/books/summ90-1",
}