The Bank controls interest rates by conducting daily money market operations where it buys and sells financial instruments such as bonds through competitive auctions, thereby adjusting for excesses or shortages of funds in the money market that may arise, for example, from changes in the supply of banknotes and public funds.
In fact, the abundance of global savings – whether induced by the globalisation of economic processes or by the aging of a large share of the world population – is indeed one of the explanations advanced for the exceptionally low bond yields recently observed in the U.S. and, to a lesser extent, also in the Euro area.