"Economics is a difficult subject, because we cannot conduct controlled experiments. There are not two or three Argentina's, one following the experiment that I described above, and another adopting the policies that I prefer. But we do have a wealth of experience from which to draw inferences. This wealth of experience all points in one direction: Keynes's teachings are still very much alive, and Argentina today would be in far better shape if his lessons had been taken to heart."
January 1, 1970
https://en.wikiquote.org/wiki/Keynesian_economics