@inbook{NBERc8648,
 Crossref = "NBERkapl00-1",
 title = "Consolidation in the Medical Care Marketplace,A Case Study from Massachusetts",
 author = "Jason Barro and David M. Cutler",
 BookTitle = "Mergers and Productivity",
 Publisher = "University of Chicago Press",
 pages = "9-50",
 year = "2000",
 month = "January",
 URL = "http://www.nber.org/chapters/c8648",
}
@book{NBERkapl00-1,
 title = "Mergers and Productivity",
 author = "Steven N. Kaplan",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "2000",
 URL = "http://www.nber.org/books/kapl00-1",
}