But sometimes they  16  One complication in measuring the costs of holding reserves relates to the numeraire in which the reserves are valued. Typically and appropriately, the central bank presents its accounts in local currency terms.
The large economies of the world have all worked extremely hard over the last years to reform their banking regulation. One even speaks of a “Regulatory Tsunami.” I have myself been part of that effort by chairing the working group that proposed a reform of banking structures in the EU.