Thanks to RCTs, however, we know that $100 worth of free meals translates into an additional 2.8 years of educational attainment–three times as much as free uniforms. Speaking of proven impact, deworming children with intestinal complaints has been shown to yield 2.9 years of additional schooling for the absurdly small investment of $10 worth of treatment. No armchair philosopher could have predicted that, but since this finding was revealed, tens of millions of children have been dewormed.
