Brad DeLong and Paul Krugman are doing a superb job of reminding us of the continued relevance of Keynesian thinking. But they are hampered by the absence of micro-founded models that plausibly deliver the Keynesian remedies they advocate. The economics profession doesn't take an argument seriously until the argument can be laid out with a well-specified modelRodrik noterar såklart att Krugman i andra sammanhang argumenterat övertygande för varför det är nyttigt att formalisera sina teorier i enkla modeller. Problemet med makroekonomi är att många enkla formella modeller saknas på många ganska centrala plan. Exempelvis när det gäller pengar, vilket gör att fråga sig på vilken grund Krugman kokat ihop sitt recept mot krisen: Spend, spend, spend.
Rodrik återger en talande anekdot:
The failures of contemporary macro theory remind me of the time we were interviewing a highly touted graduate student on the academic job market (I believe he was from the University of Minnesota, but I am not totally sure). We asked him how he would teach macro to public policy students at the Kennedy School. He thought for a while, and said: "I guess I would do it all using the overlapping-generations model, and since this is an introductory course, I wouldn't bring money in at all." Enough said.
