I have an economics back ground, not sure about it being the most widely accepted or what that even means.
Anyway moving on I is.
Offshoots of his theory are also new Keynesian economics, multiplier effect, and debt neutrality. So why it is the most studied and you should know this.
To understand thought and philosophical views you have to realize nothing happens in a vacuum. Previous thought is built upon prior with a common foundation.
It is like trying to fully understand Marxism and not looking how he built upon Hagel and Hagel built upon Aristotle.
Most widely accepted means can you show me a government in this world that does not subscribe to total spending and government intervention in the economy? Can you show me a nation without a central bank and money being created by borrowing it into existence?