00374pab a2200121 454500008004000000100002000040245009600060260000900156300001500165362001100180650002400191773003700215180718b2014   xxu||||| |||| 00| 0 eng d  aBiddle, Jeff E.  aThe cyclical behavior of labor productivity and the emergence of the labor hoarding concept  c2014  ap.197-212.  aSpring  aLabour productivity  aJournal of Economic Perspectives