Macro-economics has so many variables included that it is more of a religion than a science.  

Keynesian economics was the religion de jour when I was at Duck U.  

"monetary policy actions by the central bank and fiscal policy actions by the government, can help stabilize output over the business cycle.  Keynesian economists often advocate an active role for government intervention during recessions."  sounds familiar.  

Then there are the fans of   Monetarism.

And we shouldn't ignore the  "Lucas critique of Keynesian economics" partially relying on the Modigliani–Miller theorem and the Ricardian equivalence.


But for about 6 plus years of the recent Obama administration, the central bank sat on its collective interest rate at the very bottom so those interest rate interventions were non-existent.  

So many theories; so little proof that any of them connect to reality!