The Impact of Interest Rates on
Bank Protability: A Retrospective Assessment
Using New Cross-country Bank-level Data
Callan Windsor, Terhi Jokipii and Matthieu Bussiere
International Banking Research Network contributors:
Callan Windsor and Marcus Miller (Australia); Yaz Terajima (Canada); Alejandro Jara (Chile);
SimonaMalovana (Czech Republic); Stefano Ungaro (France); Henrike Michaelis (Germany);
CaoJin (Norway); Gajewski Krzysztof (Poland); Li Jieying (Sweden);
Terhi Jokipii and Javier Rodriguez-Martin (Switzerland)
Research Discussion Paper
RDP 202305
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The Impact of Interest Rates on Bank Profitability: A Retrospective
Assessment Using New Cross-country Bank-level Data
Callan Windsor*, Terhi Jokipii** and Matthieu Bussiere***
International Banking Research Network contributors:
Callan Windsor and Marcus Miller (Australia); Yaz Terajima (Canada); Alejandro Jara (Chile);
Simona Malovana (Czech Republic); Stefano Ungaro (France); Henrike Michaelis (Germany); Cao Jin (Norway);
Gajewski Krzysztof (Poland); Li Jieying (Sweden); Terhi Jokipii and Javier Rodriguez-Martin (Switzerland)
Research Discussion Paper
2023-05
June 2023
*Reserve Bank of Australia
**Swiss National Bank
***Banque de France
We would like to thank Anthony Brassil, Meredith Österholm, Linda Goldberg, Mattia Girotti,
Viktors Stebunovs, Guillaume Horny, Laurent Clerc, Philippe Billard and participants at the
Summer 2021 International Banking Research Network Meeting for their helpful comments and
suggestions. The views expressed in this paper are those of the authors and do not necessarily
reflect the views of contributing central banks. The authors are solely responsible for any errors.
Authors: windsorc at domain rba.gov.au, terhi.jokipii at domain snb.ch and Matthieu.BUSSIERE at
domain banque-france.fr
External Communications: rbainfo@rba.gov.au
https://doi.org/10.47688/rdp2023-05
Abstract
This paper provides a retrospective assessment of the relationship between bank profitability and
interest rates, focusing on the period when rates were very low or negative. To do this we use new
confidential bank-level data covering about 1,500 banks operating in 10 banking systems, with most
samples spanning the two decades up to the end of 2019. Our analysis confirms the empirical
regularity that declining interest rates reduce banks’ net interest margins. However, we find a smaller
effect than in previous studies: on average across countries, a 100 basis point fall in short-term
interest rates results in a 5 basis point decline in net interest margins in the short run. Notably, there
are substantial cross-country differences, and, in some cases, the estimated effect is greater.
Importantly, the effect of lower interest rates on net interest margins is larger than the effect on
asset returns, suggesting that banks can shield overall profitability in the face of lower interest rates.
For example, lower interest rates alleviate debt-servicing burdens and are associated with a fall in
provisions set aside to cover losses on loans. There is therefore no one-size-fits-all result for the
impact of low interest rates on overall profitability: in some jurisdictions banks maintained their level
of profitability as the beneficial impact of lower rates on loan-loss provisions and other factors,
including an increased focus on cost efficiencies and streamlining business models, materially offset
the drag from lower interest margins.
JEL Classification Numbers: E52, F34, F36, G21
Keywords: interest rates, bank profitability, net interest margin, monetary policy
Table of Contents
1. Introduction 1
2. Overview of the Data and Methodology 2
3. Literature on Bank Profitability and Interest Rates 3
4. Channels of Monetary Policy to Bank Profitability 4
4.1 Other factors 5
5. Data Description 7
6. Analytical Framework 12
7. Empirical Findings across Countries 13
7.1 Net interest margins 13
7.2 Overall bank profitability 21
7.2.1 Overall bank profitability: quantitative results in more detail 23
8. Conclusion 24
Appendix A: Summary of Selected Bank-level Papers 25
References 26
1. Introduction
For much of the past decade, interest rates in many countries were at or near historically low levels.
This raised questions about the consequences of low interest rates for bank profitability and
implications for the transmission of monetary policy. While interest rates have risen more recently
due to high inflation, this paper provides a retrospective assessment of the effect of low interest
rates on bank profitability. The challenges and consequences of low rates may arise again at some
point in the future, particularly given the neutral rate is estimated to have fallen significantly in
advanced economies over the past few decades (Holston, Laubach and Williams 2017). This paper
is unique in using proprietary bank-level data for 10 countries, with the effect of lower interest rates
on bank profitability estimated by banking sector experts from each country.
This paper presents new insights on the
direct
impact of lower rates on bank profitability, after
controlling for other factors that operate indirectly through monetary policy's independent impact on
aggregate demand.
1
All else equal, lower interest rates are likely to directly impact bank profitability
by eroding banks’ net interest margins (NIMs). This is because most bank assets earn a rate of
interest that varies to some extent with the policy rate. However, some bank liabilities, including
equity and transaction deposits, pay no or little interest and banks may choose not to reprice
transaction deposits in line with the policy rate. As a result, lower interest rates are likely to lower
NIMs. Moreover, the impact on margins could be larger in low-rate environments, when rates are at
or near their effective lower bounds. This is because of the higher share of deposits at low rates
that banks choose not to reprice lower in line with lending rates. The impact on margins could also
be larger if rates have been lower for longer as interest rate hedges become less effective over
time.
2
While NIMs will tend to decline with interest rates, the overall direct impact on bank profitability is
not obvious (CGFS 2018). Lower interest rates can decrease loan-loss provisions by reducing the
cost of servicing debt and lowering default probabilities. Banks can also respond endogenously by
increasing their non-interest income (for example, fee income) and reducing their costs of operating.
Ultimately, teasing out the balance of these effects is an empirical question.
Quantifying the impact of lower rates on bank profitability and its components is relevant for
policymakers. On the one hand, lower profits erode banks’ ability to build capital buffers to absorb
future losses. Lower capital can also weigh on lending (Gambacorta and Shin 2018), with reduced
credit availability potentially weighing on economic activity. In a theoretical model, Brunnermeier
and Koby (2018) propose a reversal rate below which further reductions in the policy rate become
contractionary under specific conditions.
3
This is because of the negative effects of lower profitability
on bank capital and the associated contractionary effects on bank lending. On the other hand, if
banks choose to protect their profitability by not lowering interest rates on their lending after a fall
in the policy rate then this could impair the transmission of monetary policy. Central banks have
1
While we are only concerned with estimating the direct impact of lower rates, it is important to recognise that lower
interest rates
indirectly
contribute to higher bank profits by stimulating economic activity.
2
Banks in some jurisdictions engage in interest rate swaps to hedge interest rate risk stemming from holding a greater
amount of fixed-rate liabilities relative to fixed-rate assets. However, these hedges become less effective when rates
have been lower for longer because they gradually roll onto lower interest rates.
3
These include banks being subject to an occasionally binding equity constraint (and so being unable to raise external
equity) as well as being net investors in debt securities.
2
acknowledged these potential side effects and have in some cases adapted their operations in low-
rate environments to lower the burden of low or negative interest rates on bank profitability.
4
2. Overview of the Data and Methodology
This paper summarises the association between interest rates and bank profitability using unique
confidential bank-level data across 10 countries. These data were made accessible as part of a
collaboration between 10 central banks organised by the International Banking Research Network
(IBRN).
5
Each participating central bank in the IBRN examined the association between interest rates
and bank profitability using a common methodology that takes into account underlying economic
conditions as well as differences in banks’ business models. This paper also draws on qualitative
information obtained from a survey of each contributing central bank. The survey asked respondents
to describe, among other things, the impact of low rates on banks’ profits; actions taken by banks
to mitigate any negative impact; and various features of the operating environment, such as the
interest rate structure of banks’ assets.
The use of confidential bank-level data complemented by the survey information sharpens
existing cross-country empirical evidence on the association between rates and profitability. Previous
studies have tended to rely on commercially available databases such as BankScope or S&P Global
Market Intelligence’s SNL Financial, which use strict criteria to ensure all variables are consistently
reported across countries.
6
While this consistency is invaluable to researchers, it typically results in
more missing observations and smaller sample sizes. Conversely, the use of confidential data gives
our banking sector experts more flexibility to adjust sample sizes and adjust the construction of
particular variables to best represent the underlying concept of interest. For example, the use of
confidential bank-level data for Australia made available to central bank researchers by the
prudential regulator significantly increases the available sample size and reduces the incidence of
missing observations. Our research goal, and the main contribution of this paper, is to use the best
available data to answer our research question and add a degree of nuance to existing cross-country
work in this area by drawing on the insights from our qualitative survey.
Relative to previous approaches, our estimation strategy is akin to a completely flexible cross-country
panel regression, in which every independent variable is allowed to vary by country. By allowing our
estimated effects to vary by country under a common methodology, we are better able to compare
results between countries relative to other large cross-country studies using estimates obtained from
a pooled cross-country sample. We focus on four different dependent variables: the return on assets
(ROA), the NIM, non-interest income (Non-II) and loan-loss provisions (LLPs). This way we can
better identify the channels through which low and negative interest rates affect profitability. In
contrast to previous research, we also permit country-specific thresholds for what are considered
4
See, for example, Mario Draghi’s quote from 27 March 2019: We will continue monitoring how banks can maintain
healthy earning conditions while net interest margins are compressed. And, if necessary, we need to reflect on possible
measures that can preserve the favourable implications of negative rates for the economy, while mitigating the side
effects, if any. That said, low bank profitability is not an inevitable consequence of negative rates. The proportionality
assessment of non-conventional measures and the need to counteract undesirable side effects is explicitly mentioned
in the Strategy Review of the ECB, which was concluded in July 2021 see the overview note (ECB 2021).
5
Further information on the IBRN can be found on its official website (https://www.newyorkfed.org/ibrn).
6
See, for example, Borio, Gambacorta and Hofmann (2017), CGFS (2018) and Claessens, Coleman and Donnelly (2018).
Altavilla, Boucinha and Peydró (2018) use a mix of proprietary data in conjunction with data from several commercial
providers, but only focus on the euro area.
3
low interest rate episodes and identify these from the history of short-term interest rates within each
country. A common definition of ‘low’ across all countries – such as the 1.25 per cent threshold used
in Claessens
et al
(2018) would mean that several countries in our sample such as Australia,
Canada and Chile only spend limited periods of time below the low-rate threshold. Country-specific
thresholds ensure there is sufficient within-country variation in interest rates within the low-rate
environment to identify any nonlinear effects.
7
While the magnitude of any nonlinear effects (should
they exist) could differ between countries depending on the proximity of their low-rate thresholds
to zero our approach allows these effects to be identified for all countries in the sample.
Furthermore, we separately examine whether prolonged low or negative interest rates
disproportionately impair bank profitability. Finally, the richness of our data allows us to disaggregate
banks by size: large, global banks defined here as the 80 or so banks that are included in the
Bank for International Settlements global systemically important banks (G-SIB) assessment sample
could have the capacity to better shield their profit margins in a low interest rate environment,
and we can test this empirically.
8
The general result that all else equal lower policy rates decrease margins is much clearer for the
NIM than for ROA, suggesting that many banks can partially offset the effect of low interest rates
on overall profitability. Our results for banks’ LLPs suggest that lower rates reduce debt-servicing
burdens. There also appear to be subtle nonlinearities in low interest rate environments and results
tend to indicate that the reaction of bank profitability to interest rate changes can differ between
larger, often more sophisticated banks, relative to their smaller peers. More broadly, a key finding
from this work is that there is not a one-size-fits-all answer to the impact of monetary policy on
overall bank profitability. The qualitative information obtained with the abovementioned survey also
informs some of these cross-country differences.
The rest of the paper is organised as follows. Section 3 reviews the relevant literature. Section 4
discusses the main channels that link interest rates to bank profitability. Section 5 presents the data
and key stylised facts. Section 6 turns to the analytical framework and empirical strategy followed
in the paper. The results are presented in Section 7. Section 8 concludes the paper.
3. Literature on Bank Profitability and Interest Rates
There is widespread empirical support that lower interest rates are associated with a decline in
banks’ NIMs. However, there is less agreement on the impact of monetary policy on overall bank
profitability as well as the impact of negative rates.
9
Table A1 summarises some of the existing bank-
level studies. One goal of this paper is to bring the best available bank-level data to bear on these
questions and tie together the seemingly disparate evidence about the impact on overall profitability
and nonlinear effects when short-term interest rates are below zero.
Starting with the impact on banks’ interest margins, several studies identify a nonlinear relationship
between interest rates and NIMs, with the marginal impact of a cut to the cash rate larger in low
interest rate environments see, for example, Borio
et al
(2017). A prolonged period of low rates is
7
Throughout this paper, we capture ‘nonlinear’ effects by allowing the linear impact of rates on profitability to change
if the bank is operating in a low-rate regime.
8
As defined by the Basel Committee on Banking Supervision, see <https://www.bis.org/bcbs/gsib/gsib_assessment_samples.htm>
for details of the sample.
9
See, for example, Borio
et al
(2017), Claessens
et al
(2018), Altavilla
et al
(2018), Bikker and Vervliet (2018),
CGFS (2018) and Beauregard and Spiegel (2020).
4
also found by several studies to have a larger negative effect on margins than a relatively short
period see, for example, Claessens
et al
(2018).
However, there is less consensus in the literature on the impact of monetary policy on overall
profitability. Several country-specific papers find modest effects of lower interest rates on bank
profitability for example, Alessandri and Nelson (2015) for UK banks and Busch and
Memmel (2015) for German banks while larger impacts are reported in cross-country studies for
example, Borio
et al
(2017). In contrast, other papers find a negligible effect of interest rates on
bank profitability. For example, Genay and Podjasek (2014) and Bikker and Vervliet (2018) both find
that interest rates have a negligible effect on US banks’ profitability, mainly because higher fees and
lower LLPs offset downward pressure on NIMs.
In recent years studies have focused specifically on the effect of negative rates on bank profitability,
with no common ground established. For Denmark and Sweden, Turk (2016) finds that the
profitability of banks was resilient following the introduction of negative interest rates, at least in the
short and medium term, as does Basten and Mariathasan (2018) for Swiss banks. Focusing on a
large cross-country sample of European and Japanese banks, Lopez, Rose and Spiegel (2020) report
that the benign implications of negative rates for bank profitability were because banks were able
to offset interest income losses under negative rates with gains in non-interest income, including
fees and capital gains. By contrast, Rostagno
et al
(2019) estimate that euro area bank profitability
would have been lower in counterfactual scenarios in which the policy interest rate remained at zero
or above. Urbschat (2018), Molyneux, Reghezza and Xie (2019) and Beauregard and Spiegel (2020)
find that negative interest rates reduce bank profitability in the longer run, partly because of banks’
limited ability to pass on negative rates to depositors or otherwise adjust their business models.
4. Channels of Monetary Policy to Bank Profitability
A banks overall profitability, as measured by its ROA, can be decomposed simplistically according
to the identity below see Brassil (2022) for a more complete decomposition:
( ) ( )
- , where
AL
t t t t t A L L
i A i L E
ROA Non II NIM LLP NIM i i i
AA

+ = +


In this identity,
ROA
,
-Non II
,
and
LLP
are defined as a share of assets. The average
interest rates on banks’ interest-bearing assets and liabilities are
A
i
and
L
i
respectively, and
A
,
L
, and
E
are the values of banks’ assets, liabilities and equity. This decomposition motivates us to
examine not only the association between interest rates and ROA, but also the association with
NIMs, Non-II and LLPs. This allows us to unpack the channels through which changes in interest
rates and the slope of the yield curve affect overall profitability. These channels are considered in
detail below.
NIMs: As interest rates fall a larger share of bank deposits pay very low interest rates. This can
squeeze NIMs because as rates fall, deposits that already receive zero or very low interest rates
have not been repriced lower in line with lending rates or the return on liquid assets. This is especially
true if market rates become negative, as banks may be unable to adjust deposit rates. There is also
a mechanical association between interest rates and banks’ NIMs. This occurs because a share of
banks’ funding is from equity, which does not bear interest. This limits the extent to which a
5
reduction in interest rates flows through to lower funding costs and mechanically reduces NIMs. To
see this, note that in the identity above, even with constant spreads, the
falls as the level of
interest rates declines. The slope of the yield curve also matters, as banks’ loans and other assets
typically have longer durations than their liabilities.
The impact of policy rates on profits is also likely to vary by bank size. Large banks have more
complex business models and more diverse sources of income which may make them more nimble
in shoring up profitability as NIMs decline. Larger banks also tend to rely less on deposit funding
and more on market-based sources of funding, and so their NIMs could be expected to compress
less when interest rates decline because of the effective lower bound on deposit rates. This
hypothesis is consistent with the idea that larger banks with global operations are more insulated
from changes in monetary policy (Cetorelli and Goldberg 2012).
Non-II: The reduction in NIMs could be offset by changes in Non-II. When interest rates fall, banks
gain from the revaluation of longer-term assets given their role in maturity transformation and the
associated positive duration gap between assets and liabilities. Banks can also offset lower NIMs
through other endogenous adjustments to the way they operate. For instance, banks can pivot to
Non-II-generating activities as well as increase their fees.
LLPs: Low interest rates may also affect LLPs. Lower rates make the existing stock of debt easier
to service, thereby reducing overall debt burdens and estimated probabilities of default (PDs). These
PDs are an important input into banks’ forward-looking provisioning models. On the other hand, low
interest rates may also lower the quality of new loans through the risk-taking channel of monetary
policy. The literature on a risk-taking channel of monetary policy suggests falling interest rates can
increase risk-taking by banks in three ways. First, lower profits and sticky nominal return targets can
increase banks’ willingness to extend loans to riskier borrowers (Rajan 2006; Haldane 2011). Second,
higher income and collateral values may lead to falling risk perceptions (Jiménez
et al
2014). And
finally, forward guidance by central banks might reduce risk premia in low-rate environments (Borio
and Zhu 2012). However, a risk-taking channel of monetary policy (to the extent that it matters) will
only affect the flow of new loans. Given the stock of variable-rate loans is larger than the flow, lower
interest rates are expected to lower provisions.
4.1 Other factors
Several other factors mean the channels outlined above are unlikely to have a uniform impact across
countries.
Funding behaviour: Differences in the composition of banks’ liabilities will affect the impact of
very low rates on profits. Funding from wholesale markets (such as bonds) is not constrained by the
zero lower bound in contrast to what has been observed for deposit funding. As a result, banks that
rely more heavily on wholesale funding markets are less likely to be affected by a reduction in the
policy rate from already low levels. Macroeconomic and institutional factors mean that some banking
systems make greater use of wholesale funding relative to others. For instance, the Australian,
Norwegian and Swedish banking systems are less reliant on deposit funding relative to their
international peers, which could be expected to attenuate the impact of lower rates on profitability,
all else equal.
6
Prevalence of fixed rate loans: Countries with a higher share of fixed-rate lending are likely to
be more affected by changes in the slope of the yield curve relative to countries with a higher share
of variable-rate loans. For example, in France, fixed-rate loans comprise around 9095 per cent of
the stock of lending. This contrasts with other countries such as Canada, where the stock of fixed
rates is around one-half, and Sweden and Australia where the share is lower still.
Hedging: Likewise, in countries where hedging is less common for example, countries in the euro
area; see Hoffmann
et al
(2019) movements in the yield curve are likely to have a larger impact
on bank profits. Ordinarily, NIMs will narrow when yield curves flatten because banks are exposed
to interest rate risk from maturity mismatches because of borrowing short and lending long. The
extent to which banks reduce their exposure to this risk by hedging will impact their sensitivity to
changes in the yield curve.
Banks are also exposed to interest rate risk stemming from holding a greater amount of fixed-rate
liabilities (such as non-interest bearing deposits) relative to fixed-rate assets, such that when interest
rates decline net income from these positions falls. Banks can choose to hedge this risk using swaps
whereby the bank receives cash flows linked to fixed rates and pays cash flows linked to variable
rates. As a result, when variable rates decline the income from these hedges increases, thereby
providing the necessary hedge. The extent to which some banking systems use interest rate swaps
to hedge this risk will also cause differences in the pass through of lower rates to profits in the short
run.
10
Competition: Banks operating in countries with less competitive banking systems will have more
pricing power. As a result, following a cut to cash rates, these banks can ensure the fall in their
lending rates is closer to the decrease in their funding costs, leaving NIMs less affected than
otherwise similar banks operating in more competitive environments.
Central bank term funding facilities: The introduction of various funding schemes since the
2008 financial crisis is another factor that is likely to cause cross-country heterogeneity in the
responsiveness of bank profits to lower rates. Term funding schemes involve providing low-cost,
longer-term funding to banks, often with incentives for banks to increase their lending to the private
sector. These schemes have been used as an alternative tool to provide stimulus when policy rates
are near their effective lower bounds. Differences in the availability of these schemes, their design
features and take-up across countries are likely to drive differences in the impact of low rates on
bank profitability.
Tiered rates in the implementation of monetary policy: Finally, another measure that can be
deployed by central banks to address the side effects of low/negative interest rates is a so-called
tiering system. For example, the ECB introduced tiering in September 2019 to support the bank-
based transmission of monetary policy. Under this scheme, banks’ holdings of excess liquidity were
exempted from the negative deposit rate facility. As explained later, this system is particularly
relevant for French and German banks (both included in our sample) who hold a large share of total
system liquidity see, for example, Baldo
et al
(2017) and Grossmann-Wirth and Hallinger (2018).
Other countries in our sample have also used similar schemes, including Norway and Switzerland.
10
In the long run these hedges become less effective and so are unlikely to drive cross-country differences in the long-
run responsiveness of bank profits to changes in the cash rate.
7
5. Data Description
The current project is conducted under the auspices of the IBRN, a network of central bank
researchers who focus on global banking. To examine the impact of interest rates on banks’
profitability, we rely on confidential bank-level data. Each country’s data are only available to subject
matter experts from that country’s central bank and we rely on the expert judgement of each
contributor to construct the most appropriate sample for their jurisdiction.
Details of the sample for each country are provided in Table 1. Around 1,500 banks across the
10 jurisdictions are examined, with a bank broadly defined as an institution whose business is to
receive deposits and/or close substitutes and grant credits or invest in securities on their own
account. Most jurisdictions use data at a quarterly frequency, although some use semiannual and
annual data. Seven countries use unconsolidated banking data, with the decision to rely on
consolidated versus unconsolidated data left to subject matter experts from each central bank. While
most data series start in the early 2000s or earlier, for Sweden they start only in 2010.
Table 1: Key Statistics for the Country Samples
AUS
(a)
CAN
CHL
CZE
FRA
DEU
NOR
POL
SWE
CHE
Start date
2003
1994
2004
2002
2000
2000
2000
2000
2010
2000
Frequency
QoQ
QoQ
QoQ
QoQ
HoH
YoY
YoY
QoQ
YoY
YoY
No of banks
181
76
13
21
562
203
221
23
56
104
No of time periods
68
104
62
72
40
20
20
80
10
20
Consolidation
C
C
UC
UC
UC
UC
UC
UC
C
C
Low-rate threshold
2.0
1.2
2.8
0.5
1.2
1.2
1.6
1.9
0.9
0.2
Negative rates
No
No
No
No
Yes
Yes
No
No
Yes
Yes
Windsorisation (%)
1
1
1
1
10
1
0.5
1
5
1
Notes: International Monetary Fund country abbreviations: AUS: Australia; CAN: Canada; CHL: Chile; CZE: Czech Republic;
FRA: France; DEU: Germany; NOR: Norway; POL: Poland; SWE: Sweden; CHE: Switzerland.
(a) Sample includes banks, credit unions and building societies, foreign branches and foreign subsidiaries.
Source: Contributing central banks
Table 2 provides a full list of variables used in our analysis. Unlike previous studies, our definition of
a low-rate environment is country-specific, defined as the 25th percentile of each country’s historical
rate distribution. In choosing the most appropriate time period over which to define low rates we
again rely on our participating subject matter experts, with the sample period not necessarily the
same as that shown in Table 1. The low-rate threshold for each central bank is plotted in Figure 1.
8
Table 2: Definitions
Term
Definition
Panel A: Dependent variables
Return on assets (
ROA
)
The ratio of net income expressed as a percentage of average total assets
(ATA).
Net interest margin (
NIM
)
The ratio of net interest income (NII) expressed as a percentage of average
interest earning assets (AEA). NII includes gross interest and dividend income
minus total interest expense. AEA is the sum of total loans, total securities,
investments in property and earning assets not otherwise categorised,
including non-current assets held for sale which are not loans.
Non-interest income (
-Non II
)
The ratio of Non-II expressed as a percentage of ATA. Non-II is the value of
operating income from continuing operations for the reporting period,
excluding the value of interest income and interest expense.
Loan-loss provisions (
LLP
)
(a)
The ratio of LLPs (or impairment expenses) to cover non-performing loans
expressed as a percentage of ATA. This is a flow item from the income
statement.
Panel B: Variables of interest
Short-term interest rate
Three-month interbank rate.
Spread
Difference between the 10-year sovereign bond yield and the 3-month interest
rate.
Low-rate dummy variable
Equal to 1 when the 3-month interbank rate is in the first quartile of the
country-specific historical rate distribution.
Lower-for-longer variable
The number of consecutive years that a country’s 3-month interest rate is in
the low period.
Large bank dummy
(b)
Equal to 1 if the bank is in the group of global banks that made the main G-SIB
assessment sample.
Panel C: Baseline bank controls
Deposits over liabilities
The ratio of deposits and short-term funding (STF) expressed as a percentage
of total liabilities. Deposits and STF include total customer deposits, deposits
from banks, money market instruments, certificates of deposit and other
deposits.
Liquid assets over total assets
The ratio of cash, liquid assets and securities expressed as a percentage of
ATA. Securities include reverse repos and cash collateral, trading securities, all
in-the-money trading derivatives and derivatives recognised for hedging (less
the value of netting arrangements), available for sale securities, held to
maturity securities, at-equity investments, and other securities.
Equity ratio
The ratio of total equity expressed as a percentage of ATA. Total equity
includes common equity, non-controlling interest, securities revaluation
reserves, foreign exchange revaluation reserves, and other revaluation
reserves.
Panel D: Baseline macro controls
Real GDP growth
Year-on-year growth in real GDP.
CPI growth
Year-on-year inflation.
Housing price growth
Year-on-year growth in housing prices (apartments and houses).
Notes: (a) Canada uses the stock of provisions.
(b) For Poland the large bank dummy variable is equal to 1 for Polish subsidiaries of G-SIB banks. For Sweden a bank is
classified as a large bank if it is included in main assessment sample at least once during the time period 201418. For
Germany and the Czech Republic the dummy is equal to 1 for all domestic systemically important banks.
Source: Contributing central banks
9
Figure 1: Policy Rates
Notes: AUS: Australia; CAN: Canada; CHL: Chile; CZE: Czech Republic; FRA: France; DEU: Germany; NOR: Norway; POL: Poland;
SWE: Sweden; CHE: Switzerland.
(a) Does not show the full history over which the low-rate threshold was calculated for some countries.
Source: Contributing central banks
Trends in profitability for the mean and median banking systems in the sample are plotted in
Figure 2. Despite the broad-based decline in short-term interest rates over the sample, on average
across the countries examined in this paper, banks’ ROAs were largely unchanged over the sample,
although volatile around the financial crisis in 2008. By contrast, the median NIM has been declining
over the past decade, consistent with the decline in policy rates. For both the NIM and ROA the
median is more volatile than the mean, suggesting there is substantial heterogeneity in country
experiences.
10
Figure 2: Trends in Bank Profitability
Average of contributing central banks
Note: Australia, Canada, Chile, Czech Republic, France, Germany, Norway, Poland, Sweden (from 2010) and Switzerland.
Source: Contributing central banks
For a cursory and preliminary look at the association between changes in interest rates and
profitability, Figures 3 and 4 plot the period-to-period change in NIMs and ROAs against the change
in interest rates for the mean bank in all countries. There appears to be a positive association
between changes in interest rates and banks’ NIMs; however, there is no equivalent relationship for
banks’ ROAs. This preliminary evidence, along with the trends presented in Figure 2, is consistent
with the idea that banks’ may have shielded the impact of lower rates on overall profitability by
increasing fee-based business and reducing costs. This notwithstanding, these bivariate associations
fail to control for a host of relevant factors, including country and bank fixed effects as well as other
relevant balance sheet controls, motivating our much more careful assessment of these relationships
in the next section.
Net interest margins
2013
2007
1.8
2.0
2.2
2.4
2.6
2.8
%
Mean
Median
Return on assets
2013
2007
2019
0.5
0.7
0.9
1.1
1.3
1.5
%
Mean
Median
11
Figure 3: Policy Rates and NIMs
Notes: Australia, Canada, Chile, Czech Republic, France, Germany, Norway, Poland, Sweden (from 2010) and Switzerland. First and
last percentile of the distribution removed.
Source: Contributing central banks
Figure 4: Policy Rates and ROAs
Notes: Australia, Canada, Chile, Czech Republic, France, Germany, Norway, Poland, Sweden (from 2010) and Switzerland. First and
last percentile of the distribution removed.
Source: Contributing central banks
-4
-2
0
2
4
-0.50
-0.25
0.00
0.25
0.50
0.75
Change in interest rates ppt
Change
inNIMs
ppt
-4
-2
0
2
4
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
Change in interest rates ppt
Change
inROAs
ppt
12
6. Analytical Framework
In this project, 10 central banks estimate the same regressions using bank-level data for their
country that is, Equation (1) below is estimated separately for each country. Our baseline model
is a variant of the specification used in Borio
et al
(2017):
, 0 1 , 1 2 3 4 5 6 7
8 9 10 11
1 2 , 1 ,
i t i t t t t i t t t i
t t i t t t i t t i
t i t i i t
profit profit r spread low large r low r large
r low large spread low spread large spread low large
YX
= + + + + + + +
+ + + +
+ + + +
(1)
Here
,it
profit
is the profit of bank
i
in period
t
. In our baseline specification,
profit
is measured
as the ROA. We also explore specifications in which profit is replaced by one of its underlying
components the
,
-Non II
and
LLP
.
The variables of interest are the 3-month interest rate,
t
r
, and the spread between the yield on
10-year government bonds and the short-term rate,
t
spread
, as well as their interactions. The
coefficient
6
on the interaction term
tt
r low
indicates the differential impact a change in the short-
term rate has on the profitability of smaller banks when interest rates are low.
t
low
is a dummy
equal to 1 if the home country in a specific year
t
is in a low-rate environment. In our baseline
specification, we consider a country to be in a low-rate environment when its 3-month interest rate
is in the first quartile of the country’s sample distribution (Figure 1). The coefficient
7
on the
interaction term between
t
r
and the
i
large
dummy indicates the differential impact a change in the
policy rate has on profitability for large banks compared to their smaller counterparts in a normal
rate environment. The
i
large
dummy is equal to 1 if the bank is in the group of around 80 global
banks that made the BIS’ main G-SIB assessment sample for the end-2019 G-SIB exercise. Finally,
the coefficient
8
on the triple interaction term
t t i
r low large
indicates the differential impact of
a change in short-term rates in a low-rate environment for larger banks compared to their smaller
counterparts. All of these interactions are repeated for the spread between the 10-year rate and the
3-month rate,
t
spread
.
t
Y
are macroeconomic controls and consist of real GDP growth, housing price growth and CPI
inflation.
,1it
X
are bank-level controls that include deposits over total liabilities, the liquidity ratio
and total equity capital over total assets, all lagged one period (definitions are provided in Table 2).
These controls remove any correlation interest rates might indirectly have with profitability via their
impact on the state of the economy and funding conditions. Bank-level controls are lagged one
period as bank profitability could have a contemporaneous impact on these controls.
i
are bank
fixed effects and
,it
is an error term. We use robust standard errors, clustered by bank to
accommodate within-bank serial correlation.
In addition to the baseline regression given by Equation (1), contributing central banks estimated
two additional regressions. The first of these replaces the
t
low
dummy with a variable that captures
for how long interest rates have been low. A longer period of low interest rates could be expected
to increase the negative effect of lowering rates on profitability because interest rate hedges become
less effective in a protracted low-rate environment. The second of these replaces the
t
low
dummy
with a dummy variable for whether rates are negative. Negative interest rates could have a
13
detrimental effect on banks’ profitability because of banks’ limited willingness to pass along negative
rates to depositors.
Each contributing country estimated this model over their confidential data using a fixed effects (FE)
estimator. Because of the lagged dependent variable we have relaxed the strict exogeneity
assumption (
( )
1
, , , 0
it i iT i
E controls controls
) and our regressors are instead weakly
exogenous (
( )
,0
it is i
st
E controls
=
) , assuming
it
is serially uncorrelated. The implication of
non-strictly exogenous regressors is that the FE estimator is downward biased. However, when the
time period is reasonably large, as it is here for most jurisdictions, this bias is negligible. This
notwithstanding, estimates obtained for Germany, Norway, Sweden and Switzerland should be
considered lower bounds.
Finally, the dynamic specification used in Equation (1) allows us to examine the short- and long-run
impact of changes in policy rates on profitability. The longer-term impact of a permanent change in
interest rates on profitability for small banks is given by the expression
( )
21
/1

which is obtained
by recursively substituting for
,1it
profit
in Equation (1).
The benefit of the simple baseline specification used here is it could be easily communicated to each
central banking expert and commonly estimated over their own confidential bank-level data.
However, this simplicity means we necessarily omit a number of other interactions that might have
been interesting to explore. First, additional evidence might be obtained by interacting the interest
rate level and the slope of the yield curve with bank-specific variables, such as excess reserves and
deposit dependence, which both could increase the sensitivity to rates. We also do not control for
expected macroeconomic conditions. Others have argued that policy and profitability might share a
common association with expected economic conditions, and failing to control for these could result
in biased estimates (Altavilla
et al
2018). For example, improvement to the economic outlook could
give rise to higher rates and profitability by stimulating investment and increasing current loan
demand. On the supply side, banks might also increase their profitability by increasing their business
lending as the improved economic outlook translates into lower credit risk. While these channels are
plausible, finding good controls for expected demand that are consistently available across countries
is challenging (beyond controlling for current economic conditions). Finally, our specification
assumes that bank profitability does not affect monetary policy decisions. As noted in Borio
et al
(2017), while aggregate banking conditions might affect the stance of monetary policy, the
profitability of any given bank is unlikely to affect central bank decisions. This is a key feature of
running our baseline regression at the bank level, rather than aggregating across all banks for a
given country and estimating a time series regression.
7. Empirical Findings across Countries
7.1 Net interest margins
In line with expectations, our estimates point to a clear positive relationship between the short-term
interest rate and banks’ NIMs during normal times: a fall in the interest rate is associated with a fall
in NIMs. From our sample of 10 countries spanning around 1,500 banks, the estimates suggest that
during normal times, a 100 basis point reduction in short-term interest rates reduces smaller banks’
14
NIMs by around 5 basis points in the short run (Table 3 top panel; Figure 5, top panel).
11
The mean
long-run impact, calculated using the expression towards the end of Section 6, which assumes the
change in interest rates is permanent, is much higher, at around 15 basis points.
12
Similarly, there
is broad-based evidence that a flattening of the yield curve (as measured by the spread between
10-year and 3-month interest rates) is associated with lower NIMs. Our findings are broadly
consistent with those reported by Claessens
et al
(2018) for their sample spanning 47 countries, but
is noticeably smaller than the impact reported in Borio
et al
(2017) for their sample of large,
advanced economy banks.
We find limited evidence that the effect of interest-rate changes differs for larger banks compared
to smaller banks (Table 3, top panel; Figure 5, bottom panel), though Germany, Canada and
Australia are exceptions. In Germany, the expected positive association between short-term interest
rates and margins is only evident for larger banks. By contrast, larger Canadian banks’ margins
appear completely insulated from changes in the short-term interest rate, reflecting the higher
degree of diversification between interest and non-interest income. Likewise, in Australia, the impact
of a reduction in interest rates on the margins of larger banks is significantly lower relative to smaller
banks, possibly reflecting their greater use of wholesale funding markets.
Figure 5: Monetary Policy and Banks’ NIMs
Impact of a 100 basis point cut to the policy rate
Notes: AUS: Australia; CAN: Canada; CHL: Chile; CZE: Czech Republic; FRA: France; DEU: Germany; NOR: Norway; POL: Poland;
SWE: Sweden; CHE: Switzerland.
(a) Large banks defined as those in the BIS main G-SIB assessment sample.
Source: Contributing central banks
11
The full regression outputs are available upon request.
12
This figure is obtained using the average coefficient on the lagged dependent variable,
1
, in Equation (1), which is
0.7.
Smaller banks, normal rate environment
-10
0
10
bps
-10
0
10
bps
Marginal impact of being a larger bank
(a)
CAN
CHE
NOR
AUS
CZE
FRA
POL
CHL
DEU
SWE
-20
-10
0
10
%
-20
-10
0
10
%
Significant (p-value 0.1) Insignificant
Table 3: Results for Low Rate and Large Bank Interactions
(
continued next page
)
AUS
CAN
CHL
CZE
DEU
FRA
NOR
POL
SWE
CHE
Net interest margin (
NIM
)
r
0.070***
0.160***
0.017
0.068***
0.038
0.024**
0.101***
0.010
0.040
0.14***
spread
0.054***
0.044
0.014
0.049*
0.075
0.136***
0.088***
0.029*
0.281
0.08***
large r
0.056***
0.186***
0.046
0.041
0.082*
0.005
0.004
0.019
0.059
0.04
large spread
0.026**
0.334*
0.015
0.036
0.028
0.026
0.013
0.069
0.352
0.03
low r
0.024
0.069
0.184***
0.182
0.111
0.012***
0.219**
0.531*
0.319
0.04
low spread
0.040***
0.191**
0.076***
0.009
0.025
0.002
0.273***
0.039
0.382*
0.01
large low r
0.021
0.270*
0.052
0.254
0.215***
0.026***
0.589
0.336
0.294
0.78**
large low spread
0.012
0.318*
0.052
0.023
0.012
0.033
0.206*
0.053
0.467
0.50*
Observations
6,940
4,830
696
1,274
2,909
12,380
3,092
1,249
408
1,857
Within R
2
0.790
0.705
0.842
0.571
0.471
0.690
0.565
0.895
0.492
0.73
Return on assets (
ROA
)
r
0.063***
0.047
0.009
0.064**
0.064
0.042***
0.014
0.017*
0.237
0.01
spread
0.046***
0.159*
0.043**
0.037
0.043
0.012
0.167***
0.030**
0.190
0.04*
large r
0.067***
0.069
0.013
0.047
0.003
0.012
0.122***
0.013
0.077
0.38***
large spread
0.110***
0.150*
0.003
0.108**
0.010
0.000
0.516***
0.025
0.414
0.10
low r
0.008
0.280
0.026
0.045
0.453**
0.051
0.014
0.116
0.556**
0.04
low spread
0.021
0.207
0.011
0.050
0.197
0.048*
0.272**
0.029
0.217
0.07
large low r
0.002
0.029
0.105**
0.396
0.356
0.003
0.288
0.071
0.183
0.05
large low spread
0.265**
0.126
0.005
0.051
0.232
0.010
0.944**
0.039
0.463
0.52
Observations
6,940
4,830
696
1,274
2,909
12,380
3,092
1,249
408
1,857
Within R
2
0.164
0.173
0.812
0.105
0.092
0.250
0.184
0.279
0.178
0.19
15
Table 3: Results for Low Rate and Large Bank Interactions
(
continued
)
AUS
CAN
CHL
CZE
DEU
FRA
NOR
POL
SWE
CHE
Non-interest income (
-Non II
)
r
0.102***
0.091
0.028*
0.055**
0.111
0.175***
0.021***
0.045***
0.128
0.05***
spread
0.059***
0.113
0.031*
0.038
0.158**
0.105**
0.014*
0.044**
0.046
0.02
large r
0.037**
0.012
0.001
0.053**
0.029
0.115*
0.000
0.012
0.062
0.22**
large spread
0.048**
0.045
0.021
0.045
0.029
0.112
0.001
-0.009
0.223
0.20
low r
0.050**
1.190*
0.016
0.077
0.101
0.234
0.077
0.126
0.312
0.09**
low spread
0.061***
0.367
0.010
0.007
0.105*
0.016
0.035
0.097***
0.058
0.02
large low r
0.074***
0.864
0.154*
0.183
0.082
0.120
0.123
0.240
0.068
0.08
large low spread
0.160**
0.283
0.063
0.008
0.102
0.276*
0.222
0.004
0.121
0.55
Observations
6,940
4,830
696
1,274
2,909
12,380
3,092
1,249
408
1,857
Within R
2
0.439
0.719
0.815
0.392
0.181
0.450
0.456
0.873
0.604
0.54
Loan-loss provisions (
LLP
)
r
0.015***
0.031***
0.017
0.009
0.128
0.009***
0.062***
0.062**
0.017
0.00
spread
0.007*
0.024***
0.001
0.056***
0.138
0.009***
0.045***
0.102***
0.162
0.00
large r
0.023***
0.027***
0.012
0.002
0.075
0.017***
0.024
0.018
0.028
0.07***
large spread
0.078***
0.026**
0.021
0.030
0.042
0.021***
0.029
0.075
0.081
0.25**
low r
0.039***
0.109**
0.055
0.269*
0.236*
0.010
0.235**
0.671**
0.032
0.01
low spread
0.008
0.010
0.033
0.006
0.343**
0.008
0.157**
0.044
0.119
0.01
large low r
0.050*
0.120**
0.041
0.247
0.064
0.011
0.354
0.018
0.064
0.18**
large low spread
0.155***
0.001
0.024
0.029
0.101
0.030***
0.379
0.127
0.023
0.13
Observations
6,940
4,830
696
1,274
2,909
12,380
3,092
1,249
408
1,857
Within R
2
0.083
0.894
0.845
0.944
0.189
0.160
0.157
0.886
0.356
0.24
Notes: ***, ** and * denote a positive coefficient and significance at the 1, 5 and 10 per cent levels, respectively. Explanatory variables are presented for regressions run with return on assets
(
ROA
), net interest income (
NIM
), non-interest income (
-Non II
) and loan-loss provisions (
LLP
) separately. Coefficients on the lagged dependent variable, bank-level controls,
macroeconomic controls as well as dummy variables for
low
,
large
,
low large
are omitted for brevity. Full regression results are available upon request.
Source: Contributing central banks
16
17
During low interest rate periods, and for most countries, the relationship between the short-term
interest rate and NIMs is not statistically distinguishable from that during normal times. In fact, for
France, Norway and Poland a further reduction in the cash rate from already low levels appears to
have a relatively lower impact on NIMs. For larger banks operating in a low-rate environment, the
available evidence tends to suggest that a further reduction in short-term interest rates has a
relatively lower impact on NIMs for banks in Germany, France and Switzerland.
13
This is despite the
distribution of liquidity in the euro area, which sees large banks from core countries tending to hold
large amounts of liquidity in the deposit facility, which should make them more sensitive to
reductions in interest rates.
14
One explanation for this is the ECB’s tiering scheme, which may have
shielded larger euro area banks’ NIMs, although this is unlikely to be a major driver of our results
given it was introduced only towards the end of our sample period. Another factor that could have
contributed to this result is the increase in high margin lending that was facilitated by the introduction
of the Targeted Longer-Term Refinancing Operations II program (Jobst and Lin 2016). Between
June 2016 and the end of the period studied, French and German banks could borrow up to 30 per
cent of the volume of eligible private non-mortgage loans for a four-year period at the prevailing
main refinancing operations (MRO) rate, which was 0 per cent. With lower short-term interest rates
compressing NIMs, banks reacted by increasing loan volumes, which were funded at the MRO rate.
The increase in volumes led to an increase in NIMs given the favourable spread between lending
rates (positive) and the MRO rate (0 per cent).
Next, we examine the effect of policy rates that are not just briefly low but low-for-long. In these
regressions, we replace the low dummy variable (a binary variable equal to 1 when interest rates
are low and zero otherwise) with a low-for-long variable, equal to the number of time periods during
which interest rates have been low. The motivation for doing this is that the nonlinear effects one
may expect in a low interest rate environment may materialise with a delay, perhaps because interest
rate hedges become less effective over time.
15
The results are reported in Table 4. To facilitate
comparison with the low interest rate findings, Table 4 compares the coefficients for the variables
of interest from both specifications: the low-for-long results are in bold, directly below the low
interest rate coefficients as reported in Table 3. For brevity, we do not report the coefficients of the
non-interacted variables (the interest rate, the yield curve, the dummy for large banks interacted
with the interest rate and the yield curve) as they are almost identical to those of Table 3. These
additional results are available upon request.
13
By contrast, for large Canadian banks, there is an interesting nonlinearity: while a rate reduction in normal times does
not appear to affect their profitability, a reduction from already low levels is detrimental. This suggests there could be
limits to the benefits of diversification for larger Canadian banks.
14
The ECB deposit facility rate reached zero in July 2012; it became negative in 2014; and was set to 0.40 per cent in
2016 and 0.5 per cent in 2019.
15
Here we are assuming the marginal impact of being in a low-rate environment changes linearly with the amount of
time spent in the low-rate environment. If the impact is nonlinear then it is unclear whether the dummy or our linear
variable is a better approximation of the true nonlinear effect.
Table 4: Results Comparing the Low and Low-for-long (LFL) Rates
AUS
CAN
CHL
CZE
DEU
FRA
NOR
POL
SWE
CHE
Net interest margin (
NIM
)
low r
0.024
0.069
0.184***
0.182
0.111
0.012***
0.219**
0.531*
0.319
0.04
LFL
0.006***
0.008
0.060**
0.478
0.024***
0.125***
0.105*
0.090
1.510*
0.07***
low spread
0.040***
0.191**
0.076***
0.009
0.025
0.002
0.273***
0.039
0.382*
0.01
LFL
0.005***
0.040**
0.030***
0.029
0.003
0.043***
0.099***
0.002
omitted
0.01**
large low r
0.002
0.270*
0.052
0.254
0.215***
0.026***
0.589
0.336
0.294
0.78***
LFL
0.003
0.000
0.050*
1.050*
0.249*
0.031
0.031
0.031
0.140
0.12
Return on assets (
ROA
)
low r
0.008
0.280
0.026
0.045
0.453**
0.051
0.014
0.116
0.556**
0.04
LFL
0.009***
0.021
0.002
0.770
0.967**
0.010
0.057
0.146
0.348
0.00
low spread
0.021
0.207
0.011
0.050
0.197
0.048*
0.272**
0.029
0.271
0.07
LFL
0.005***
0.026
0.002
0.009
0.135
0.017
0.095**
0.001
omitted
0.00
large low r
0.010
0.029
0.105**
0.396
0.356
0.003
0.288
0.071
0.183
0.05
LFL
0.002
0.008
0.042**
0.991
0.660
0.004
0.054
0.084
0.035
0.37***
Non-interest income (
-Non II
)
low r
0.050**
1.190*
0.016
0.077
0.102
0.234
0.077
0.126
0.312
0.09**
LFL
0.001
0.123
0.012
0.381
0.195
0.084
0.017
0.053
0.713
0.01
low spread
0.061***
0.367
0.010
0.007
0.105*
0.016
0.035
0.097***
0.058
0.02
LFL
0.006***
0.051
0.003
0.024
0.111***
0.010
0.006
0.007***
omitted
0.01
large low r
0.024
0.864
0.154*
0.183
0.082
0.120
0.123
0.240
0.068
0.08
LFL
0.001
0.111
0.057
1.086**
0.331
0.036
0.058
0.234
0.069
0.06
Loan-loss provisions (
LLP
)
low r
0.039***
0.109**
0.055
0.269*
0.236*
0.010
0.235**
0.671**
0.032
0.01
LFL
0.007***
0.019***
0.019
0.555***
0.931***
0.001
0.058*
0.427**
0.354
0.01
low spread
0.008
0.010
0.033
0.006
0.343**
0.008
0.157**
0.044
0.119
0.01
LFL
0.003***
0.007*
0.013
0.024
0.114
0.004*
0.038*
0.003
omitted
0.00
large low r
0.088***
0.120**
0.041
0.247
0.064
0.011
0.354
0.018
0.064
0.19**
LFL
0.002
0.020**
0.003
0.495**
0.007
0.012**
0.165
0.247
0.101
0.14***
Notes: ***, ** and * denote a positive coefficient and significance at the 1, 5 and 10 per cent levels, respectively. Explanatory variables are presented for regressions run with return on assets
(
ROA
), net interest income (
NIM
), non-interest income (
-Non II
) and loan-loss provisions (
LLP
) separately. Coefficients are only presented for the interaction term of interest. Full
regression results are available upon request.
Source: Contributing central banks
18
19
The main takeaway from Table 4 is that the results using the low-for-long variable are qualitatively
similar to those using the low dummy. Starting with the effect on the NIM in the top panel, the
coefficient of the interacted variable is significant for more countries using the low-for-long variable,
suggesting that the effect of low interest rates on NIMs is nonlinear and larger when rates have
been kept low for a while. In the case for Australia, Chile, Germany and France, NIMs decline as
rates are kept lower-for-longer; however, for Norway, Sweden and Switzerland the reverse is true.
For the other dependent variables (discussed in more detail in the next section) there is some weak
evidence that the impact of a rate reduction on ROA starts to exert itself slightly more after a period
of time (e.g. for smaller Australian and German banks). But overall, the results using the low-for-
long variable are similar to those using the low dummy for both ROA and LLPs. For Non-II, there is
no evidence of lower-for-longer impacts.
Finally, there is mixed evidence that negative rates exacerbate the detrimental impact of low interest
rates on banks’ NIMs. In two of the four jurisdictions that have implemented negative short-term
interest rates, the marginal impact of a cut to the interest rate is significantly larger in negative-rate
environments (Table 5). For German banks, by contrast, a further cut to the short-term rate when
it is already negative has a beneficial impact on larger banks NIMs. For smaller banks, it is the
opposite.
One important caveat to this analysis is the limited within-country variation in policy rates once they
reach the zero lower bound, which makes it harder to identify the effect on the dependent variable.
As a consequence, results need to be interpreted with caution. Still, the results indicate that there
is no clear-cut nonlinearity below zero, which is consistent with the mixed findings from the existing
literature.
20
Table 5: Results with Negative Rate and Large Bank Interventions
DEU
FRA
SWE
CHE
Net interest margin (
NIM
)
r
0.018
0.036***
0.331***
0.12***
spread
0.142***
0.143***
0.623***
0.10***
large r
0.010
0.018**
0.164
0.04
large spread
0.096***
0.009
0.347
0.30**
neg r
0.476***
0.181**
0.311
0.06
neg spread
0.013
0.142***
0.163
0.15
large neg r
0.484***
0.147
0.331
0.32
large neg spread
0.019
0.124*
0.425
0.15
Within R
2
0.473
0.680
0.491
0.74
Return on assets (
ROA
)
r
0.002
0.041***
0.190
0.02
spread
0.105
0.006
0.694***
0.04*
large r
0.090**
0.004
0.050
0.28
large spread
0.027
0.002
0.405
0.26*
neg r
0.409
0.125
1.473**
0.01
neg spread
0.231*
0.076
0.101
0.02
large neg r
0.416
0.009
0.372
0.18
large neg spread
0.113
0.017
0.691
0.25
Within R
2
0.085
0.250
0.177
0.19
Non-interest income (
-Non II
)
r
0.009
0.102***
0.130
0.06
spread
0.036
0.035
0.264
0.01
large r
0.013
0.042
0.105
0.02
large spread
0.018
0.052
0.211
0.09
neg r
0.529***
0.225
0.916*
0.07
neg spread
0.121**
0.246
0.274
0.01
large neg r
0.480**
0.168
0.385
0.10
large neg spread
0.241
0.303
0.261
0.05
Within R
2
0.185
0.450
0.604
0.55
Loan-loss provisions (
LLP
)
r
0.033
0.004**
0.022
0.01
spread
0.022
0.003
0.167
0.00
large r
0.103***
0.003
0.044
0.07
large spread
0.118**
0.005
0.082
0.02
neg r
0.370
0.044
0.006
0.02
neg spread
0.214*
0.021
0.106
0.01
large neg r
0.531
0.061
0.258
0.30
large neg spread
0.103
0.163***
0.092
0.18
Within R
2
0.182
0.170
0.356
0.24
Notes: ***, ** and * denote a positive coefficient and significance at the 1, 5 and 10 per cent levels, respectively. Explanatory
variables are presented for regressions run with return on assets (
ROA
), net interest income (
NIM
), non-interest income
(
-Non II
) and loan-loss provisions (
LLP
) separately. Coefficients on the lagged dependent variable, bank-level controls,
macroeconomic controls as well as dummy variables for
neg
,
large
,
low large
are omitted for brevity. Full regression
results are available upon request.
Source: Contributing central banks
21
7.2 Overall bank profitability
In Section 7.1, we observed the relationship between short-term interest rates and banks’ NIMs
during normal times to be positive and significant, as expected. The effect of lower interest rates on
overall bank profitability (as measured by banks’ ROAs) is less clear owing to other mitigating factors.
Both Table 3 (second panel) and Figure 6 (second panel) show the results for our ROA regression.
Our results confirm that there is not a clear-cut association between lower interest rates and overall
bank profitability; for about half the sample a reduction in short-term interest rates lowers bank
profitability, while for the other half it is associated with an increase in profits. The magnitude of the
impact of monetary policy on overall profitability is modest. The largest impact among the
10 countries examined is that a 100 basis point fall in the short-term interest rate is associated with
a 6 basis point reduction in smaller banks’ ROAs in the short run. These estimates would be smaller
still if one were to add back any effects that operate indirectly through monetary policy's effect on
aggregate demand.
Figure 6: Effect of Monetary Policy
Impact of a 100 basis point cut to the policy rate for smaller banks in a normal rate environment
Note: AUS: Australia; CAN: Canada; CHL: Chile; CZE: Czech Republic; FRA: France; DEU: Germany; NOR: Norway; POL: Poland;
SWE: Sweden; CHE: Switzerland.
Source: Contributing central banks
NIM
-15
0
15
bps
-15
0
15
bps
ROA
-15
0
15
bps
-15
0
15
bps
Non-II
-15
0
15
bps
-15
0
15
bps
LLPs
CAN
CHE
NOR
AUS
CZE
FRA
POL
CHL
DEU
SWE
-30
-15
0
15
bps
-30
-15
0
15
bps
Significant (p-value 0.1) Insignificant
22
There is only limited evidence that Non-II has played a counterbalancing role (Table 3, third panel;
Figure 6, third panel). That is, there is no consistent result across countries indicating that non-
interest income increases as interest rates fall, either owing to one-off revaluations of long-term
assets or banks shifting their business towards non-interest sources of income. Nor does the non-
interest income effect appear to be significantly different for larger banks or during low-rate periods.
Our results do, however, show that lower rates uniformly lower LLPs by reducing debt-servicing
burdens on the stock of existing debt (Table 3, fourth panel; Figure 6, fourth panel). There is no
evidence that this effect is meaningfully offset by an increase in risk-taking by banks during low-rate
periods (i.e. a risk-taking channel of monetary policy), which would instead result in a positive and
significant coefficient on LLPs.
There is considerable country-specific heterogeneity underlying these key results. Some of these
quantitative
differences are discussed in the next sub-section, including the impact on overall
profitability when rates are negative.
To
qualitatively
inform some of the cross-country differences and unpack some of the attenuating
factors that have enabled banks to maintain their level of overall profitability as short-term rates
have fallen, we can turn to the insights received from our
qualitative survey.
Overall, the responses
received point to a range of mitigating actions, including banks striving to become more cost efficient
and streamlining their business models.
For example, starting first with Canada, responses from our survey indicate that banks whose NIM
was affected by the low interest rate environment took considerable measures to safeguard profits
by becoming more cost efficient, selling non-core underperforming businesses and pivoting to focus
on higher growth areas in the short term. Moreover, in some cases, banks adjusted the pricing of
assets/liabilities to preserve spread (e.g. lower deposit rates) to mitigate the impact on margins.
For larger Swiss banks, the survey noted that fee and commission income accounts for the largest
share of their operating income, with revenues coming mostly from wealth and asset management
businesses. As such, their overall profitability was less affected by the impact of the low-rate
environment on interest rate margins and benefited from fee and commission revenue streams. For
individual Swiss banks, the survey pointed to evidence of search-for-yield behaviour among smaller
banks when interest rates were low and negative as they increased mortgage volumes and took on
more risk. Some banks also grew their fee and commission business, particularly in the low interest
rate environment.
The
qualitative survey
responses highlight that in Poland there was little discernible impact of lower
rates on overall profitability due to banks increasing the share of more profitable credit products
(e.g. consumer loans); a reduction in less profitable credit products; and a decrease of the interest
on liabilities. The NIM in Poland remained relatively high compared to other EU countries, which was
also related to the level of interest rates in Poland remaining significantly higher than the zero lower
bound. In addition, while fee and commission margins have declined in part due to statutory and
regulatory activities aimed at increasing consumer protection by reducing the costs incurred by them
banks were able to reduce their operating costs partly through digitalising processes.
23
In Australia, lower rates do appear to lower bank profitability. However, the size of this effect is not
economically significant. Several factors, highlighted in the
qualitative survey
, help to explain this
result. Around one-third of Australian banks’ funding comes from wholesale markets, which is a
larger share than for many international banks. The cost of wholesale funding is not constrained by
an effective zero lower bound in contrast to what has been observed for deposit interest rates
internationally. Moreover, Australian banks tend to have interest rate hedges, which smooth profits
and so delays the reduction in profits from falls in interest rates. Moreover, around three-quarters
of Australian banks' assets are variable-rate loans that are funded with variable-rate deposits and
other debt. The implication of this is that changes in the slope of the yield curve do not have a large
impact on Australian banks' profits.
7.2.1
Overall bank profitability: quantitative results in more detail
At the individual country level, several channels are at play. In Canada, Switzerland and Norway
there is suggestive evidence that banks have taken measures to offset the low-rate impact on NIMs
to safeguard ROAs. That is, in these jurisdictions, the effect of lower interest rates on NIMs has not
transferred through to ROAs (Table 3; Figure 6). For Switzerland and Norway, the effect on bank
profitability of larger banks differs significantly from smaller banks, with larger banks benefiting from
lower rates.
In the case of France, the rate impact on ROAs is almost double in size relative to the impact on
NIMs. In the case of the Czech Republic, the magnitude of the rate impact on ROAs is similar in
magnitude to that for NIMs but is not statistically significant. However, for the Czech Republic this
result does not hold in the low-rate environment. Additional tests indicate that the positive
association between NIMs and interest rates only holds when rates are increasing, suggesting banks
in the Czech Republic shielded themselves against rate decreases, including through lower loan-loss
provisions.
In negative interest rate regimes, we find no clear evidence that the impact of policy on overall
profitability is any different, with exceptions for Germany and to some extent Sweden. In Germany,
a decline in short-term interest rates reduces ROAs for smaller banks during the low interest rate
regime, whereas it seems insignificant during the negative interest rate regime. The insignificant
impact might arise from two sub-components of ROAs the NIM and Non-II that seem to
counterbalance each other: on the one hand, smaller banks seemed to have safeguarded profits by
increasing their Non-II (for example, fee and commission income), while on the other hand their
NIM declined (Michaelis 2022). This suggests that small banks in Germany found means to shield
overall profitability in the face of negative interest rates. The story is different for Sweden. Here, a
rate cut during the negative interest rate regime reduces ROAs for smaller banks by much more
than during the low interest rate regime.
24
8. Conclusion
This paper has provided an empirical analysis of the effect of lower interest rates on bank profitability
including differential responses when rates are very low looking back at the period when central
banks lowered interest rates to mitigate the risks of deflation. At the time, particular concerns were
raised about possible nonlinear effects of low interest rates in the neighbourhood of the effective
and zero lower bounds. Banks tend not to reduce deposit rates below a certain threshold, a threshold
which may vary across jurisdictions and over time. Because of this, lower interest rates may
significantly affect bank profitability near these bounds and hamper monetary policy transmission.
It is therefore of utmost importance for policymakers and researchers to carefully assess the
magnitude of this effect.
Based on bank-level data for 10 different countries, we have investigated these effects empirically
with a consistent methodology between countries, focusing on different measures and components
of profitability (NIM, ROA, Non-II and LLPs). A key takeaway from this investigation is that the effect
of a decline in interest rates on bank profitability is small, economically speaking. The immediate
effect of a 1 percentage point decrease in the short-term interest rate on NIMs is only 5 basis points.
While this hides sizeable cross-country differences (and the long-run effect is closer to 15 basis
points), the measured effect is lower than previous estimates.
We find some evidence of nonlinearities in low interest rate environments, but only for a handful of
countries in the sample. More importantly perhaps, we find that the effect of low interest rates on
ROAs is smaller than on NIMs, suggesting that banks have found ways to offset the effect of lower
interest rate margins. In addition, holding interest rates lower for longer does not appear to change
the results noticeably. Similarly, focusing on the countries that moved interest rates into negative
territory yields coefficients that are not economically large. Overall therefore, the evidence presented
here points to smaller effects of falling and low policy rates on bank profitability than previously
estimated.
25
Appendix A: Summary of Selected Bank-level Papers
Table A1: Summary of Selected Bank-level Papers
Paper
Sample
Data
Method
Main findings
Borio,
Gambacorta and
Hofmann (2017)
Sample: 14 advanced
economies
Banks: 109; large
international
Time period: 19952012
BankScope
Dynamic
panel
regressions
Lower rates are associated with lower
profits
Lower rates lower net interest
income, which more than offsets
positive impact on non-interest
income and loan-loss provisions
Claessens,
Coleman and
Donnelly (2018)
Sample: 47 countries
Banks: 3,385
Time period: 200513
BankScope
Panel with FE
regressions
Lower interest rates lower bank
profitability
Impact is larger for net interest
margins compared to overall
profitability
Altavilla,
Boucinha and
Peydró (2018)
Sample: euro area
Banks: 288
Time period: 200016
iBSI;
BankScope;
SNL Financial;
Bloomberg;
Capital IQ
Panel with FE
regressions
Lower rates have a negative impact
on net interest margins, which is
offset by a positive impact on loan-
loss provisions
Lower rates are not associated with
lower profits if current and expected
economic and financial conditions are
controlled for
Bikker and
Vervliet (2018)
Sample: US
Banks: 3,582
Time period: 200115
Federal Deposit
Insurance
Corporation
Panel GMM
estimation
Lower interest rates compress net
interest margins, but lower loan-loss
provisions
Lower rates are not associated with
lower profits
Molyneux,
Reghezza and
Xie (2019)
Sample: 33 OECD
countries
Banks: 7,352
Time period: 201216
Orbis
BankFocus;
SNL Financial
Panel DiD
regressions
Bank margins and overall profitability
fared worse in countries with
negative interest rate policies
Large banks were able to mitigate
negative effects; stronger adverse
effects were found in countries with
more competitive banking systems
Lopez, Rose and
Spiegel (2020)
Sample: 27 European
countries and Japan
Banks: 5,200
Time period: 201017
Fitch Global
Banking
Panel with FE
regressions
Negative rates lower net interest
income
This impact largely offset by
increases in non-interest income
stemming from ‘other income’
sources, such as capital gains on
securities
Beauregard and
Spiegel (2020)
Sample: 27 European
countries and Japan
Banks: 5,300
Time period: 201018
Fitch Global
Banking
Panel with FE
regressions
A protracted period of negative rates
reduces bank profitability, primarily
due to banks’ reluctance to pass
negative rates along to retail
depositors
26
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