00373pab a2200133 454500008004000000100001900040245006500059260000900124300001300133362001100146650002000157700002500177773003700202180718b1999   xxu||||| |||| 00| 0 eng d  aGaynor, Martin  aChange, consolidation, and competition in health care market  c1999  ap.141-64  aWinter  aHealth services  aHaas Wilson, Deborah  aJournal of Economic Perspectives