HES: RE: QUERY--All pre-1936 economists were laissez faire advocates?

[Rod Hay]

What was new in Keynes was not the advocacy of public works during the 
depression. Many had done that before him.
He did not invent aggregate demand. Malthus, J.A. Hobson and many others 
had written about it.

But his work was more than a synthesis of previous thought.

The Keynesians introduced the multiplier (the idea that the increase in 
aggregate demand would be larger than the increase in public spending), 
and the idea of the liquidity trap.

Friedman understood the essence of Keynes' arguments and his work 
attacked precisely these features.

Rod Hay