"...that private sector decisions sometimes lead to inefficient macroeconomic outcomes which require active policy responses by the public sector, in particular, monetary policy actions by the central bank and fiscal policy actions by the government, in order to stabilize output over the business cycle."In practice, on the fiscal policy side, this amounts to calls for increased government borrowing and spending, and sometimes reduced taxation.
One important part of the Narrative for those who believe (or believe in) Keynesian Economics is that what brought the world in general, and the United States in particular, out of the Great Depression, was the stimulative effect of the greatly increased federal government spending due to WWII.
Maybe so (or maybe not), but let's consider the other side of the equation. In 1943, during the midst of WWII, Paul Samuelson (Nobel Prize in Economics, 1970) wrote[1]:
"When this war comes to an end, more than one out of every two workers will depend directly or indirectly upon military orders. We shall have some 10 million service men to throw on the labor market. ... The final conclusion to be drawn from our experience at the end of the last war is inescapable ... were we again planning ... to shift from astronomical deficits to even the large deficits of the thirties–then there would be ushered in the greatest period of unemployment and industrial dislocation which any economy has ever faced."That is what Keynesians believed - that we faced the "greatest period of unemployment and industrial dislocation which any economy has ever faced."
Yet, we did "shift from astronomical deficits to even the large deficits of the thirties" (spending dropped from 43% to 14% of GDP) and what happened? I'll let President Truman answer [2]:
"During 1946, civilian employment approached 58 million. This was the highest civilian employment this Nation has ever known— 10 million more than in 1940 and several million higher than the wartime peak. If we include the military services, total employment exceeded 60 million. ...
"Thus, at the end of 1946, less than a year and a half after VJ-day, more than 10 million demobilized veterans and other millions of war- time workers have found employment in the swiftest and most gigantic change-over that any nation has ever made from war to peace."Samuelson's prediction based on the Keynesian narrative simply couldn't have been more wrong. Instead of the "greatest period of unemployment and economic dislocation" we had "the swiftest and most gigantic change-over that any nation has ever made from war to peace."
The Keynesian narrative was extended to handle this and other rather significant exceptions. Nonetheless, for those of us who haven't swallowed it hook, line, and sinker, it looks like the Keynesian narrative explains the relationship between government spending and economic health - except when it doesn't.
References
[1] Paul Samuelson, “Full Employment after the War,” in S.E. Harris,
ed., Postwar Economic Problems, 1943.
[2] Harry Truman, "The Economic Report of the President", page 1, issued January 8, 1947
[2] Harry Truman, "The Economic Report of the President", page 1, issued January 8, 1947