Jim Hamilton on Real Shocks

…[I] disagree with some of my colleagues is in their presumption that wage or price rigidities are the core frictions that are responsible for producing the present situation. I have in my research instead stressed technological frictions. For example, when spending on cars abruptly falls, there is a physical, technological challenge with getting the specialized labor and capital formerly employed in manufacturing cars into some alternative activity. In my mind, it is a mistake to pretend that any federal program is capable of immediately re-employing those resources into an alternative, equally productive enterprise. More fundamentally, I have suggested that our present situation is as if someone had quite successfully sabotaged the basic functionality of our financial system. Until we once again have a financial sector that can successfully allocate credit to worthy projects, we're not possibly going to be able to produce as much in the way or real goods and services, no matter what the level of aggregate demand or stimulus package might be. In terms of the textbook Keynesian models that people play with, I'm suggesting that "potential" GDP growth for 2009:Q1– that growth rate which, if we try to exceed it by stimulating aggregate demand, we primarily just get more inflation– is in fact a negative number. I do not accept the proposition that there is a level of government spending– however large a number you choose to suggest– that will prevent the unemployment rate from rising above 8%. But I do believe that if the government borrows a sufficiently large amount, we will have to worry in a very concrete way about what will sustain the foreign demand for U.S. assets.

Hamilton continues by noting that such a position is quite compatible with spending to maintain state and local government expenditures with block grants, fundamental infrastructure spending on things like the electric grid and working hard to restore the financial sector.