http://big.assets.huffingtonpost.com/ResponsetoCEA.pdf

"It is not fair or honest to claim that Professor Friedman's methods are extreme. On the contrary, with respect to forecasting method, they are largely mainstream. Nor is it fair or honest to imply that you have given Professor Friedman's paper a rigorous review. You have not.

What you have done, is to light a fire under Paul Krugman, who is now using his high perch to airily dismiss the Friedman paper as “nonsense.” Paul is an immensely powerful figure, and many people rely on him for careful assessments. It seems clear that he has made no such assessment in this case.

Instead, Paul relies on you to impugn an economist with far less reach, whose work is far more careful, in point of fact, than your casual dismissal of it. He and you also imply that Professor Friedman did his work for an unprofessional motive. But let me point out, in case you missed it, that Professor Friedman is a political supporter of Secretary Clinton. His motives are, on the face of it, not political.

For the record, in case you're curious, I'm not tied to Professor Friedman in any way. But the powerful – such as Paul and yourselves – should be careful where you step."

"What the Friedman paper shows, is that under conventional assumptions, the projected impact of Senator Sanders' proposals stems from their scale and ambition. When you dare to do big things, big results should be expected. The Sanders program is big, and when you run it through a standard model, you get a big result."