Report · RBNZ · 17 May 2022
The Financial Policy team recommends that the Financial System Oversight Committee agree in-principle to key denominator framework decisions for the Capital Review, including dual reporting, floors, and removing internal operational risk modeling. These decisions are required to provide clarity for an upcoming Quantitative Impact Study and to mitigate risks associated with opaque internal models while reducing regulatory complexity. The memorandum also outlines a conceptual approach for calibrating minimum capital requirements by balancing financial stability against economic costs, ultimately relying on political risk appetite to select the final CET1 target ratio.
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MEMORANDUM FOR Financial System Oversight committee FROM Financial Policy (Ian Woolford and Susan Guthrie) DATE June 2018 SUBJECT Bringing the components of the Capital Review together FOR YOUR Decision We recommend FSO Committee:
1. Note the logistical and tactical connections between progressing the Capital Review
and our short-term priorities and BAU activities;
2. Agree, in-principle, to the key denominator framework decisions;
3. Note the conceptual approach to incorporating the different components of the Capital
Review, and provide feedback on whether this is a useful approach. Overview
1. This paper provides:
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3. Essentially, the first two stages address the capital calculation framework: the
requirements for which capital instruments can count as regulatory capital (the numerator) and proposals for what can or cannot be calculated under the Internal Models approach, dual calculation and reporting of RWA, the imposition of a floor and so on (the denominator of the capital ratio).
4. The third stage (the ratio) can be thought of as a calibration exercise, where we can
determine the desired degree of conservatism in the overall capital framework (e.g. what are the floors), having settled on the calculation components, along with the role of buffers, including capital ratio requirements (e.g. should CET1 be 4.5 percent or higher?). It is the time to look holistically at the framework, and, ultimately, calibrate to reflect the desired risk appetite.
5. To be clear, in and of themselves decisions on these framework issues are expected
to have both capital and more general cost impacts on the banks. In some cases the direction of the costs are clear (but not yet the quantum). Dual reporting would have IT and process system impacts that will impose costs on the IRB banks and will take time to implement. On the other hand, the net impact of requiring IRB banks to standardise some models is less certain. For example, there is a general presumption that capital would increase somewhat under the standardised operational risk framework, but on the other hand it is much simpler to calculate and can be expected to result in potentially material cost savings; to a lesser degree the same may be true for the proposed standardisation of some internal models.
6. We would also draw a distinction between capital increases arising out of framework
changes, to those that are simply a resetting of expected outcomes for an outlier bank. The situation can be thought of as a prime example of the sort of monitoring and regulatory problems with the IRB framework that we are trying to address as a part of the capital review. A decision was taken last year to address our concerns about housing capital outcomes. Therefore, any capital impact on should not be conflated with capital consequences from the Capital Review framework changes as such. (Although of course this argument doesn’t apply to system costs arising from our review.) Question: When is re-litigation not re-litigation
7. Answer: when there is a new Governor.
8. One of the options in the initial scoping paper to FSO for the Capital Review was to
do away with internal models. Governors at the time were not supportive of this option, and this was reflected in the consultation paper.
9. We do just want to pause and confirm that that position continues to hold, given this
is the first Capital Review decision paper to FSO under the new governorship.
10. We would make the point that we understand how significant removing internal
models would be for the banks.
11. We would also make the point that we can also approach the problem more laterally,
rather than simply keeping or dumping internal models. A different approach to RBNZ s105 RBNZ s105 RBNZ s105 RBNZ s105 RBNZ s105 RBNZ s105
Ref #7571859 v1.10 mitigating the risks inherent in the internal models framework is viable and attractive, especially in the New Zealand context (lightly resourced, monitored, and enforced).
12. In terms of this risk mitigation approach, it is worth making several points.
13. First, the following in-principle decisions – over and above assuming we are not
removing internal models – are designed to mitigate the risks of internal models, thereby affecting the judgement about whether it is ‘worth the candle’ to get rid of them. Probably not is the answer if our internal models framework and approach is internally coherent and appropriately calibrated. This will crucially depend on the nature, and calibration, of the dual reporting and floor decisions.
14. Second, imposing a floor is a framework decision, the question of how the floor is
calibrated is a question yet to be addressed. The floors policy offers a range of benefits, consistent with the principles underpinning this Review, including competitive neutrality (our aim is for the framework to not systematically advantage one type of bank over another) and enhanced risk management (the models will have a more ‘genuine’ use, enhanced risk identification rather than simply capital relief).
15. The US is an interesting case. They require the large banks to be internal models
banks because they argue they are sophisticated enough to do a decent job in modelling, because they are systemic, and because they think internal modelling ought to generate more information about risk that should lead to reduced probability of failure. However, they require the IRB banks to hold the greater of 100 percent of the standardised amount or the modelled amount. One way of thinking about this is as a framework overlay for any systemically important bank, rather than a straight capital charge.
16. The point is there are ways to retain the benefits of internal modelling and robustly
address our concerns other than by way of simply removing internal models from the framework, but this is best addressed as a part of the calibration discussion. In-principle decisions on the denominator consultation
17. The key in-principle decisions we are seeking are:
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20. Similarly, we need to engage with the banks on the systems impacts, not just from a
cost perspective, but also to build up a sense of the transitional times needed to implement the changes. Systems changes are always time consuming for industry, especially compliance-related changes, so we can expect lengthy transition periods, and the sooner we engage on the detail the better.
21. The way we need to obtain this information is by way of a QIS (a Quantitative Impact
Study). In order to undertake such a study we need to provide banks with clear instructions and clarity about the calculation framework. Hence, the need to make inprinciple decisions. One alternative would be to provide a range of options or scenarios, but this would mean a lot more work for industry and for us.
22. Moreover, there is inherently a reasonably high degree of optionality in calibrating the
framework that can be assessed with the information from the QIS under a single scenario. For example, the level at which the calculations are made (exposure or asset class) and the level the floor is calibrated to (see the accompanying paper for more detail). Following the QIS, a more detailed picture of the net costs of the various options can be carefully considered.
23. Note also, that we intend to bring a paper to FSO in July on the QIS, prior to sending
it to industry.
24. Second, the tactical approach embedded in the Capital Review is one of risk
mitigation (or, put another way, getting the monkey off our back2 ).
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Conceptual approach to setting minimum capital requirements
25. In addition to the information we will obtain from undertaking the QIS, we have
presented FSO with various papers that consider ‘optimal’ or empirical estimates of capital:
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Range of CET1 Ratios
Recourse to the Taxpayer in a crisis
Big Equity
Harrison Model V1
IMF Loss Avoidance
Analysis
Litterature Review
(Baseline Cases)
NZBA/PwC Analysis
Implied Appropriate Range of CET1 Ratios
Minimum Requirements- CET1 Ratio of 4.5%
Largest 5 standardised
All banks
IRB banks
Very High High Mid Low Very Low
Higher
CET1 Ratio
Lower
CET1 Ratio
Less Costly to
Taxpayer
More Costly to
Taxpayer
10% 20%
Figure One: Conceptual framework to determining the optimal level of capital
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27. For the purposes of setting capital policy, we interpret a sound and efficient financial
system to be one where:
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34. Fourthly, the level of capital deemed appropriate for the system as a whole needs to
translate to capital requirements applied to individual institutions. Some institutions will be more likely than others to have systemic effects and it will make sense to require relatively more capital of these institutions (“DSIBs”). This is something we aim to address in the ratio paper.4 Our approach
35. We do not intend to reinvent the wheel in this area, but see good reasons for
developing this analytical framework, as the range of ‘optimal’ estimates is very wide, and unique aspects of the New Zealand context must be factored into local capital settings.
36. We intend to develop a simple mathematical model of the technical policy problem,
based on the conventional literature, and to use this as a tool for analysis. In particular, we will use the model to conduct sensitivity analysis of key assumptions related to the underpinning relationships. Our hope is that the range of implied optimal CET1 ratios will be relatively narrow across moderate variations in the underlying assumptions.
37. Having identified a range of CET1 ratios that are likely to optimal (or at least offer
positive marginal benefits) we will map the ‘decision set’. The ultimate step will be to select a CET1 target ratio from this decision set. It won’t deliver the ‘right’ number, but it will provide a more unified way to consider the trade-offs given a particular risk appetite.
Figure Two: The range of ‘optimal capital’ levels
38. The minimum CET1 capital ratio requirement will be somewhat lower than the CET1
target ratio, as banks can be expected to hold a voluntary buffer above the regulatory minimum. 4 It is also our intention to narrow the gap between the RWA outcomes of standardised banks and IRB banks, for similar portfolios (IRB banks are likely to be the only candidates for ‘DSIB’ status).
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39. There is a large body of literature looking at the issue of optimal capital and the
underlying relationships. We propose incorporating the findings from this literature in our analysis, alongside the results of a Quantitative Impact Study (QIS) done in conjunction with local banks and insights from the recent stress testing exercise. Next steps
40. Figure 3 (overleaf) illustrates the next steps.
41. In the short-term, we recommend that
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Figure Three: Timeline of next steps in the Capital Review
Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Dec-18 Jul-19 APRA finalises changes to their capital framework (publishes final consultation document) APRA published two of three consultation papers for changes to their capital framework Rural Benchmarking completed APRA publishes final consultation paper Residentrial Benchmarking is Completed Response to submisisons and in principle decisions published Further analysis on options and submissions. Consultation Paper and Options Calibration decisions finalised Analysis on calibration (based on the framework decision) Numerator Paper Status: Completed Response to submissions and in-principle decisions published In-principle decisions for capital framework Further analysis on options and submisisons Consultation Paper with options published Denominator Paper Status: On-going Ratio Paper Status: To Be Started Preliminary analysis with balance sheet data and stress test results TUI model analysis Quantitative Impact Study (QIS) Analysis on international developments In principle decisions Analysis on framework details ("fine-tuning") Response to submisisons and in principle decisions published Further analysis on options and submissions. Consultation Paper and Options Analysis on capital levels Literature Review Risk-Appetite analysis Framework decisions Risk-Weight Calibration decisions
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