▁sufficient ▁increase ▁in ▁those ▁sk illed ▁workers ▁has ▁bid ▁up ▁those ▁workers ' ▁sal aries . ▁An ▁example ▁of ▁the ▁slow down ▁in ▁education ▁growth ▁in ▁America ▁( that ▁began ▁about ▁the ▁same ▁time ▁as ▁the ▁Great ▁D iver gence ▁began ) ▁is ▁the ▁fact ▁that ▁the ▁average ▁person ▁born ▁in ▁ 1 9 4 5 ▁received ▁two ▁more ▁years ▁of ▁school ing ▁than ▁his ▁parents , ▁while ▁the ▁average ▁person ▁born ▁in ▁ 1 9 7 5 ▁received ▁only ▁half ▁a ▁year ▁more ▁of ▁school ing . ▁ ▁Author ▁Tim othy ▁No ah ' s ▁" back - of - the - en velope " ▁estimation ▁based ▁on ▁" compos ite ▁of ▁my ▁discuss ions ▁with ▁and ▁reading ▁of ▁the ▁various ▁econom ists ▁and ▁political ▁scient ists " ▁is ▁that ▁the ▁" vari ous ▁fail ures " ▁in ▁America ' s ▁ ▁education ▁system ▁are ▁" respons ible ▁for ▁ 3 0 %" ▁of ▁the ▁post - 1 9 7 8 ▁increase ▁in ▁inequality . ▁ ▁Race ▁and ▁gender ▁dispar ities ▁ ▁In come ▁levels ▁vary ▁by ▁gender ▁and ▁race ▁with ▁median ▁income ▁levels ▁consider ably ▁below ▁the ▁national ▁median ▁for ▁females ▁compared ▁to ▁men ▁with ▁certain ▁ra cial ▁dem ograph ics . ▁ ▁Despite ▁considerable ▁progress ▁in ▁purs uing ▁gender ▁and ▁ra cial ▁equality , ▁some ▁social ▁scient ists ▁like ▁Richard ▁Sch a ef fer ▁attribute ▁these ▁dis cre pan cies ▁in ▁income ▁partly ▁to ▁continued ▁disc rim ination . ▁ ▁Among ▁women , ▁part ▁of ▁the ▁w age ▁gap ▁is