Paul Krugman explains Keynes to George Will

NYT

The greatness of Keynes …

… is illustrated by the trouble people who consider themselves well informed have, to this day, in understanding the basic principles of how a depressed economy works.

The key to Keynes’s contribution was his realization that liquidity preference — the desire of individuals to hold liquid monetary assets — can lead to situations in which effective demand isn’t enough to employ all the economy’s resources. When you don’t understand that principle, you end up writing stuff like this:

Obama’s “rescue plan for the middle class” includes a tax credit for businesses “for each new employee they hire” in America over the next two years. The assumption is that businesses will create jobs that would not have been created without the subsidy. If so, the subsidy will suffuse the economy with inefficiencies — labor costs not justified by value added.

That is, if the private sector wouldn’t have created a job on its own, that job shouldn’t have been created — whereas the real choice is between having workers doing something and being uselessly, destructively unemployed.

(More here. Here is the Will piece from Sunday.)