Remember history when thinking of Keynesian economics
Over at Think Markets Mario Rizzo follows the advice of Paul Krugman and discusses what Keynes has actually said about infrastructure spending (ht Greg Mankiw):
Organized public works, at home and abroad, may be the right cure for a chronic tendency to a deficiency of effective demand. But they are not capable of sufficiently rapid organisation (and above all cannot be reversed or undone at a later date), to be the most serviceable instrument for the prevention of the trade cycle
So infrastructural investment is good when we are in some sort of reinforcing hole where effective demand is deficient and “will not” go back to our primary equilibrium. However, Keynes appears to be deriding infrastructural investment as a way to smooth the “economic cycle”.
I see this quote as justification for the idea that, if we have multiple pareto ranked equilibrium and a large shock government can help – but if we have a temporary shock to demand infrastructural investment is not the way (furthermore it says nothing about structural shocks, which is part of the current story). I don’t actually think this conclusion leads to an ability to dismiss either the view of Krugman, or the views of Mankiw – given that they ultimately have different beliefs on what is the proper description of the current events we are facing …
