. ▁ ▁Author ▁Tim othy ▁No ah ▁estimates ▁that ▁what ▁he ▁calls ▁" W all ▁Street ▁and ▁corpor ate ▁bo ards ' ▁pam per ing " ▁of ▁the ▁highest ▁ear ning ▁ 0 . 1 % ▁is ▁" respons ible ▁for ▁ 3 0 %" ▁of ▁the ▁post - 1 9 7 8 ▁increase ▁in ▁inequality . ▁ ▁Im m igration ▁ ▁The ▁Im m igration ▁and ▁National ity ▁Act ▁of ▁ 1 9 6 5 ▁increased ▁imm igration ▁to ▁America , ▁especially ▁of ▁non - Europe ans . ▁ ▁From ▁ 1 9 7 0 ▁to ▁ 2 0 0 7 , ▁the ▁foreign - born ▁proportion ▁of ▁America ' s ▁population ▁grew ▁from ▁ 5 % ▁to ▁ 1 1 %, ▁most ▁of ▁whom ▁had ▁lower ▁education ▁levels ▁and ▁in comes ▁than ▁native - born ▁Americans . ▁But ▁the ▁contribution ▁of ▁this ▁increase ▁in ▁supply ▁of ▁low - sk ill ▁labor ▁seem ▁to ▁have ▁been ▁relatively ▁mod est . ▁One ▁estimate ▁stated ▁that ▁imm igration ▁reduced ▁the ▁average ▁annual ▁income ▁of ▁native - born ▁" high - school ▁drop outs " ▁(" who ▁roughly ▁correspond ▁to ▁the ▁poor est ▁t enth ▁of ▁the ▁work force ") ▁by ▁ 7 . 4 % ▁from ▁ 1 9 8 0 ▁to ▁ 2 0 0 0 . ▁The ▁decl ine ▁in ▁income ▁of ▁better ▁educated ▁workers ▁was ▁much ▁less . ▁Author ▁Tim othy ▁No ah ▁estimates ▁that ▁" imm igration " ▁is ▁responsible ▁for ▁just ▁ 5 % ▁of ▁the ▁" Gre at