Who said anything about the custodian being the sovereign?

Managing the monetary system is a sovereign function, because the sovereign is the only economic actor within its jurisdiction that is solvent by fiat rather than balance sheet.

Making a monetary system without a sovereign that's actually sovereign is - eh - not wise, as the EU has been quite instructively demonstrating for the next best thing to three years now.

- Jake

If you only spend 20 minutes of the rest of your life on economics, go spend them here.