Post-crisis, the emerging view is that the crisis was caused, at least in part, by the lack of coordination and communication between the separate bodies and that it is optimal, in the interest of financial stability, to entrust the function of regulation of banks and non-banks also to central banks.
The argument is that only the monetary authority, as the lender of last resort, can provide emergency liquidity support. Also, being the regulator, the monetary authority gets a better sense of the market conditions and can therefore manage liquidity more efficiently. But this model raises fresh questions. In particular, can the central bank have exclusive responsibility for financial stability?