HomeNewsOpinionA flat yield curve does not bode well for bank margins

A flat yield curve does not bode well for bank margins

We may see bank margins taking a hit in FY 2023 as the numbers come out. If the current flat yield curve continues, then FY 2024 margins may be even lower

April 20, 2023 / 15:37 IST
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Bank margins
The overall banking sector Net Interest Margins went up from around 270 basis points in FY 2018 to about 315 basis points by FY 2022. (Image: Shutterstock/Representative)

How does the steepness of the yield curve impact the profitability of banks?  This question is fundamental to understanding the relationship between monetary policy and the economics of banks.

Banks perform three critical transformations — that of risk, maturity, and lot size. Banks accept deposits with a very high promise of security to depositors and make risky loans and investments using these deposits which is the risk transformation. Banks also generally take short term deposits and make long term loans creating what is commonly referred to as an asset liability management mismatch (ALM) which is the maturity transformation. Banks also take small deposits from consumers and make large sized loans which is the lot size transformation. All these transformations are fundamental to the functioning of banks and create risks in their operations which the regulators try to keep in check using a repertoire of regulatory instruments. Bank managements, on the other hand, try to maximise their profits while staying within the risk limits which they impose on themselves as well as those that are imposed by the regulators.

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Indian banking, like all banking systems across the world, rides on a structural ALM mismatch. The weighted average maturity of banking deposits is about 1.5 years while that of the loans is about 3 years. If we add investments to loans, then the average maturity of interest-bearing assets rises to about 4.5 years. With this level of structural maturity mismatch, a steepening yield curve will help banks improve their net interest margins (NIMs) which is the difference between the interest they earn on loans and investments, and the interest they pay on deposits divided by the total interest-bearing assets.

Figure 1 below depicts the NIMs for Indian banks for the 21-year period from 2002 to 2022 (Left hand scale) along with the term premium (right hand scale) which is difference between the one-year and the 10-year yields on government securities. The range around the average annual term premium is the range within which the daily term premia moved within the year. Clearly, this range has narrowed significantly in recent years suggesting lower volatility of the yield curve after the adoption of a flexible inflation targeting framework in FY 2016.