I was mainly talking about the U.S. reserve system. While U.K. has no reserve requirement, it has the capital requirement [1], which serves the same purpose to

I was mainly talking about the U.S. reserve system. While U.K. has no reserve requirement, it has the capital requirement [1], which serves the same purpose to limit the maximum theoretical amount of money in the system. Of course interest rate is used to further control the amount of money below the maximum theoretical limit since interest rate is an easier tool to use than the reserve/capital requirement. [1] https://en.wikipedia.org/wiki/Reserve_requirement#Countries_without_reserve_requirements https://en.wikipedia.org/wiki/Reserve_requirement#Countries_...