How Commercial Banks Use Interest Rate Spreads for Profit
This essay examines how commercial banks use interest rate spreads as their primary source of profitability. It defines the spread as the difference between interest charged on loans and interest paid on deposits, then explores the factors that complicate this simple formula — including long-term investment products, changing economic conditions, and loan defaults. The paper discusses why a spread is necessary even for non-profit institutions, using the savings-and-loan mortgage crisis as an illustrative example. It also analyzes bank-specific factors such as size, operating costs, liquidity, and credit risk that cause individual banks to maintain different spread levels.
- Introduction to Commercial Banking and Interest Rate Spreads: Defines interest rate spread and its role in bank income
- Complexities Beyond the Basic Spread Formula: Explores investment products and economic factors complicating spread
- Why a Spread Is Necessary: Costs, Defaults, and Risk: Explains loan defaults and the savings-and-loan crisis
- Bank-Specific Factors That Determine Spread Size: Analyzes size, liquidity, costs, and credit risk per bank
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What makes this paper effective
- The paper builds its argument progressively, beginning with a simple definition and equation, then systematically identifying the factors that complicate it — a logical scaffolding that makes complex financial concepts accessible.
- The savings-and-loan mortgage scandal is used as a concrete, real-world example to illustrate abstract risk concepts, anchoring the theoretical discussion in a recognizable historical event.
- The paper integrates peer-reviewed empirical research (Were & Wambua, 2014) alongside a general reference (Investopedia) to balance accessibility with academic credibility.
Key academic technique demonstrated
This paper demonstrates effective use of the "complication" technique: it introduces a straightforward concept (spread = interest charged minus interest paid), then systematically complicates and deepens it with layered considerations — investment products, economic volatility, default rates, and bank-specific variables. This approach shows readers that simple formulas rarely capture full economic realities.
Structure breakdown
The essay is organized into four paragraphs that function as implicit sections: (1) a definition and overview of interest rate spreads; (2) complications to the basic model from investment vehicles and economic change; (3) the necessity of spreads due to costs and loan defaults, supported by a historical case; and (4) a taxonomy of bank-specific factors — size, operating costs, liquidity, and credit risk — that cause individual spreads to vary. The conclusion of the final paragraph ties these factors back to competitive positioning among banks.
Introduction to Commercial Banking and Interest Rate Spreads
Commercial banks are institutions that provide services to their customers, including accepting deposits, cashing checks, lending money for various purposes, and providing investment products. Commercial banks are for-profit institutions, and while they rely on various sources of profit — including fees — their main source of profit is the interest rate spread (Investopedia, 2016). Interest rate spread refers to the difference between the interest rate charged by banks on loans to the private sector and the interest rate paid on various savings accounts. A simple numerical equation to describe the interest rate spread is: Spread = Interest Charged − Interest Paid. The interest rate paid by the bank is lower than the amount it charges to customers who have loans, and the difference between these two rates is how commercial banks derive the bulk of their income.
Complexities Beyond the Basic Spread Formula
While a bank may derive the bulk of its income from the difference between interest rates, it is incorrect to assume that the bank's income can be determined solely by examining those rates and comparing the amounts on deposit with the amount of money lent. First, while banks may change the interest paid on regular accounts with some regularity, banks also provide customers with traditional investment vehicles — such as certificates of deposit — which carry the possibility of long-term payments at a higher rate than the bank's standard interest rate if there is a dramatic change in the economy during the life of the investment product. Furthermore, interest on loans that once reflected an optimal and profitable rate of spread can become less profitable when the economy changes, a situation that might prompt a bank to lower the interest it pays on traditional savings accounts and simple investment products.
Why a Spread Is Necessary: Costs, Defaults, and Risk
It is important to realize that, even if commercial banks were non-profit entities, there would still need to be a spread between interest paid and interest charged. There are costs associated with running a bank, which must be covered through earnings. More importantly, it is critical to recognize that some percentage of money that banks lend to customers will not be repaid. Not only will the bank fail to receive interest on that money, but it will actually lose the principal. Therefore, it is important that a bank's spread be sufficiently large to cover those anticipated losses.
To understand how significant this factor is, one need only revisit the savings and loan mortgage crisis. Because unqualified borrowers received loans they had no ability to repay, the default rate on mortgages was much higher than anticipated, resulting in losses that exceeded what the spread could absorb. This was exacerbated by the fact that high-risk borrowers were often able to access the same interest rates as low-risk customers. The episode illustrates that an inadequate or poorly calibrated spread can threaten the solvency of financial institutions.
References
Investopedia. (2016). How do commercial banks make money? Retrieved February 8, 2016, from http://www.investopedia.com/ask/answers/040215/how-do-commercial-banks-make-money.asp
Were, M., & Wambua, J. (2014, December). What factors drive interest rate spread of commercial banks? Empirical evidence from Kenya. Review of Development Finance, 4(2), 73–82.
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