The need for this involvement is heightened by the entry into force in 2018 of the new standard (IFRS 9) under which banks will switch from using the concept of incurred loss to that of expected loss in order to calculate the credit portfolio provision. This standard is undoubtedly an improvement on the current situation, since it enhances the measurement of the risks of loans and receivables. At the same time, it significantly increases the complexity of calculating provisions and, thus, increases the risk of heterogeneous application across banks, which is something the supervisor should be aiming to mitigate. The work under way in the Basel Committee on this matter is therefore very timely. My comments so far imply that there are in practice significant obstacles to satisfying the legitimate expectations that a rigorous and granular supervision will help moderate the intensity of the regulatory changes needed to promote financial stability. BIS central bankers’ speeches  3  The regulatory frameworks in force and different supervisory cultures, along with the difficulty of becoming more involved in accounting practices, often place considerable limits on the intensity of supervision attainable. This explains why the actions of the authorities to prevent financial crises largely rest on the definition of clear and demanding prudential standards to underpin the work of supervisors.
Indeed that is why we took it upon ourselves to reform SONIA. We started collecting daily data on money market transactions in February 2016 from over 50 banks, building societies and investment firms. These data give us a much clearer picture than we have previously had of what is going on in sterling money markets. A subset of the data will be used for reformed SONIA. The reformed rate will be much more robust, with daily transaction volumes three to four times greater than current SONIA. Any change in SONIA’s properties will be minimal – so far the reformed rate has been around one basis point lower than on the current methodology. Another key reform is that the Bank has consulted on and will implement a changed definition for SONIA. The new definition will allow the methodology and input data of SONIA to evolve if material changes to market structure or functioning threaten to undermine the integrity of the rate. This unique feature will ensure the robustness of SONIA over the long term, giving users confidence that their contracts will not be disrupted. Let me emphasise that, from the perspective of a user of SONIA, implementing these reforms should be seamless. However, one operational consequence that users should be aware of and prepare for is that the publication time for SONIA will move from the evening of the day in question to the morning of the following day. The Bank is working with ISDA, LCH and others to ensure this change is implemented smoothly.