Brad DeLong and Robert Solow are supporters of market economies in which governments make efforts to ameliorate some the problems inherent in market economies. Milton Friedman and F. Hayec favored free market economies with a very restricted role for government involvement in the economy. Robert Solow compares the views of Friedman and Hayec and concludes that there was a good Hayec and a bad Hayec. He concludes that the good Hayec was better than the bad Friedman. Brad DeLong considers Solow's argument and concludes the opposite. He is less critical of Friedman and more critical of the bad Hayec.
The ideas of Friedman and Hayec still shape many of the economic debates that we have today. The criticisms of social democracy are a legacy from Friedman and Hayec. This article provides an historical perspective on today's debates that is well worth reading.