Educational Gaps Do Not Respond to Massive Government Spending

In a new paper researchers document that after 50 years of massive spending programs"gaps in achievement between the haves and have-nots are mostly unchanged over the past half century."
So why would you expect even more money to "solve" this problem? Isn't it more likely that there is something ingrained genetically or behaviorally that won't be erased by more of the same approach?