marginal productivity
noun[U]
ukusECONOMICS,PRODUCTION
theamountthat can beproducedbyaddingoneunitof something, such aslabour, to theproductionprocess, or theaddedprofitthat thisproduces:
Moderneconomistshaveapproachedwithcautiontheideathatmarginalproductivityaccountsfor thedemandforlabour.