In many banks the proportion of trading assets in the balance sheet increased substantially as securities and derivatives trading provided a relatively fast and flexible way to grow.9  4  Cecchetti and Kharoubi (2012), Reassessing the impact of finance on growth, BIS Working Paper 381. 5  Stein (2012) and Bolton, Santos, and Scheinkman (2012), respectively.
However, the cost-benefit calculation of non-standard measures, in particular, is quite different from that of our standard monetary policy instruments. This is why I have always cast a critical eye on government bond purchases and said that, to my mind, such large-scale purchases serve purely as an instrument of last resort to be used, for instance, to avert deflation.