00489oas 2200181z- 450 99619754520331620180813210620.0(CKB)1000000000531342(DE-599)ZDB2005416-6(EXLCZ)99100000000053134220170515cuuuuuuuu -u- -engNBER Digest OnLineNational Bureau of Economic Research (NBER)JOURNAL996197545203316NBER Digest OnLine2237211UNISA