Sadly there was no randomized evaluation, so we can't be sure. But there are good reasons to believe that Malawi's national fertilizer subsidy scheme has been successful in increasing agricultural production.
One of the main concerns of critics is the sheer cost of the scheme. In Malawi around 9% of all government spending is going on the subsidy.
What if we could get similar results for next to nothing?
That is pretty much what Esther Duflo, Michael Kremer,...