we normally recognize three major tools of Monetary Policy. What are those tools?

Question

Which one is the most powerful?

Answer 1

Changing the discount rate, changing the reserve requirements and open market operations.

It depends upon the idea of power. Altering reserve requirements can have sudden and profound effects that cascade through the economy in unexpected ways. As a consequence, it is rarely altered. Most commonly, open market operations are used because they permit finer control of variance and permit continuous adjustments to the money supply. So in a sense, open market operations are the most powerful. Regardless, in differing ways, they all acomplish the same thing.

Answer 2

The rate of interest. The supply of money. The rate of exchange. Most effective at what exactly?