This was initially a consequence of the monetary policy response to the 2008 financial crisis, particularly in the largest advanced economies. First, amid low inflation, some argued central bank independence was no longer justified. Second, as major central banks implemented quantitative easing measures, there were concerns these institutions would end up shaping fiscal policy, which is beyond their remit.
The key consequence for policy, I will argue, is that markets have become more complete, thus increasing the scope for BIS Review 81/1997  -2-  arbitrage by private agents, and decreasing the scope for the monetary authorities to use direct controls to achieve policy objectives.