Normative vs. positive models

In a very interesting piece on the fallacy of taking “the normative model of education as a true positive model” (NAP), Lant Pritchett cites Pigou:

“It is not sufficient to contrast the imperfect adjustments of unfettered enterprise with the best adjustment economists in their studies can imagine. For we cannot expect that any State authority will attain, or will even wholeheartedly seek, that ideal. Such authorities are liable alike to ignorance, to sectional pressure, and the personal corruption by private interest.”

The whole piece is here:

The Policy Irrelevance of the Economics of Education: Is ‘Normative as Positive’ Just Useless, or is it Worse?
Lant Pritchett (Harvard University, Kennedy School of Government).