Multiplicative Hogwash

The Economist offers an almost-balanced view of the Keynesian multiplier, starting with its inception in Keynes’s General Theory, its theoretical refinement by Alvin Hansen and Paul Samuelson, and subsequent theoretical and empirical work. This sums it up: “Decades after its conception, Keynes’s multiplier remains as relevant, and as controversial, as ever.” It’s relevant only in the sense that a lot of economists and policy-makers still believe in it. What it is is hogwash:

The Keynesian Multiplier: Phony Math
The True Multiplier
Further Thoughts about the Keynesian Multiplier