Money and the Multiplier Effect: How Reserve Ratios Work and Why They Matter

UPI Study › Courses › Business Essentials › Free lessons › Lesson 23.2 Free with a free account

Money and the Multiplier Effect: How Reserve Ratios Work and Why They Matter

Business Essentials · Chapter 23: Money and the Federal ReserveSection 23.2 · lesson 98 of 10511 min · free with a free account

← The Essential Functions of MoneyNext lesson: Interest Rates and Their Effect on Business Investment →

Earn 3 college credits for Business EssentialsRecommended for credit by NCCRS · Business 100 · self-paced · one payment, lifetime access

In this lesson

How reserve ratios work, and why they matter.

  • Explain how banks create money by lending
  • Calculate the deposit multiplier
  • Name the 3 factors that shrink the real expansion
  • Distinguish reserve requirements from capital requirements

Free study notes

Get this lesson's notes by email

The key points and 4 practice questions with answers, in your inbox. One email, free.

One email. Unsubscribe in one click.

Transcript

Everything said in the video, section by section (1,582 words). Read along, or search it.

Money and the Federal Reserve

Money and the Multiplier Effect

Here's a question most people never ask. Where does money in a bank account actually come from? The answer is stranger, and more important, than it first sounds. This is educational content about deposit creation and reserve requirements. It isn't financial, investment, tax, or legal advice. Reserve requirements have been changed by policymakers over time, including being set to zero at points. So any ratio in this section is illustrative only. Current requirements should always be verified. We'll see how banks create money through lending, and calculate the deposit multiplier. We'll look at the three factors that keep real expansion below the theoretical maximum. And we'll separate reserve requirements from capital requirements, which are easily confused.

The Question

Where Do Deposits Come From?

The last section established that most money is bank deposits, not physical currency. That raises an immediate question. Where do those deposits come from? The answer is that banks create them, when they lend. That isn't a figure of speech, or a loose metaphor. It describes the literal mechanics of how a bank records a loan. And it's essential to understanding how the money supply expands, and how it contracts. Once you see it, a lot of headlines about banks and credit start to make more sense. So let's walk through exactly how it works.

Fractional Reserves

Lending Creates a New Deposit

Modern banking runs on a system called fractional reserve banking. A bank holds only a fraction of its deposits as reserves. It lends the remainder to borrowers. Reserves are funds kept on hand, or at the central bank, rather than lent out. Now here's the part most people get wrong. When a bank makes a loan, it doesn't usually hand the borrower physical cash. And it isn't passing along some other depositor's funds. Instead, it credits the borrower's own deposit account with the loan amount. That creates a new deposit, one that didn't exist before the loan was made. So the act of lending is itself the act of creating a new deposit. That's the central mechanism of this whole section.

Worked Through

Deposit Creation, Round by Round

Let's work it through, with an illustrative reserve ratio of ten percent. That ratio is constructed for this exercise. It isn't any current requirement. Ten percent means the bank must hold ten percent of each deposit as reserves, and may lend the other ninety. A customer deposits one thousand dollars. The bank holds one hundred dollars as reserves, and lends nine hundred to a borrower. The borrower spends that nine hundred dollars. Whoever receives the payment deposits it in a bank. That bank holds ten percent, or ninety dollars, as reserves, and lends out eight hundred ten. And the process continues. Each round's new deposit is ninety percent of the round before it. The reserves held keep adding up, and the amount available to lend shrinks round by round.

Worked Rounds

5 Rounds From a 1,000 Deposit

Here are the first five rounds, using those same illustrative figures. Round one, the original one thousand dollar deposit. One hundred is held, and nine hundred lent onward. Round two, a new deposit of nine hundred dollars. Ninety held, eight hundred ten lent. Round three, eight hundred ten dollars deposited, and seven hundred twenty-nine lent. By round five, the new deposit has shrunk to about six hundred fifty-six dollars. Now watch the last column, the cumulative total of deposits. After just five rounds, it has passed four thousand ninety-five dollars. And as the rounds continue, it keeps climbing toward a theoretical maximum of ten thousand dollars. So one original deposit, lent and redeposited again and again, supports deposits several times its own size. That's deposit creation in concrete, worked form.

The Multiplier

The Deposit Multiplier

That theoretical maximum has a name. It's the deposit multiplier. It's the largest expansion of deposits that an initial deposit can support. You calculate it as the reciprocal of the reserve ratio. That is, one divided by the reserve ratio, expressed as a decimal. With our illustrative ratio of ten percent, that's one divided by zero point one zero. The answer is ten. So the theoretical maximum is ten times the original deposit. Ten thousand dollars, from one thousand. The relationship holds generally. A lower reserve ratio produces a larger multiplier, because banks can lend more of each deposit. A higher reserve ratio produces a smaller one, because banks must hold more back.

Table 23.2.1

Why the Real Expansion Is Smaller

In practice, that theoretical maximum rarely happens. Three factors pull real expansion below it. The first is currency held outside banks. Cash a person keeps, rather than redepositing, can't support another round of lending. Every dollar that leaves the banking system that way stops the multiplication. The second is excess reserves, reserves banks choose to hold beyond what's required. A bank doing that is lending less than the maximum, out of caution, weak loan demand, or other business reasons. The third is the most fundamental. There have to be willing, creditworthy borrowers. A bank can't create a deposit through lending if no qualified borrower seeks, or receives, a loan. Each factor works independently, and each can push the real multiplier well below its theoretical value. And in a downturn, it's the third factor that binds most tightly.

The Binding Constraint

Reserves Are Necessary, Not Sufficient

That third factor explains a pattern that can seem puzzling. Banks may hold ample reserves. They may be fully willing to lend. And yet lending, and the deposit expansion it would create, doesn't increase. Why not? Because businesses and households, worried about the outlook, aren't seeking new loans. And in weaker conditions, banks judge fewer applicants to be creditworthy. So reserves are a necessary condition for lending. But they aren't a sufficient one. That's precisely why increasing bank reserves doesn't automatically increase lending. Anyone who assumes ample reserves mean easy credit is overlooking these three factors. Especially the third.

Reserve Requirements

A Regulatory Tool That Has Changed

A reserve requirement is a regulation. It sets the minimum fraction of deposits a bank must hold as reserves. It works as a tool, influencing how much banks can lend, and so how far the money supply can expand. Here's the essential accuracy point. The reserve requirement framework has changed over time. At points, requirement ratios have been set to zero, for some or all categories of deposit. So any specific ratio must be verified with an authoritative source, never assumed to still apply. What stays constant is the mechanism. Whatever fraction is required, if any, it works by constraining how much of each deposit a bank may lend. And the multiplier logic applies to whatever ratio is actually in effect. Central banks have also shifted which tools they mainly rely on. They've moved from an emphasis on reserve requirements toward tools like interest paid on reserves, and other administered rates. We'll cover the present framework when we reach the Federal Reserve's tools.

Not The Same Thing

Reserves Versus Capital

Reserve requirements and capital requirements are frequently confused. The distinction matters. Reserves concern liquidity. Does the bank have enough readily available funds to meet withdrawals, and settle payments day to day? Capital concerns solvency. Are the bank's own resources, contributed by owners and retained from earnings, enough to absorb losses on its loans and assets? If not, it may be unable to meet its obligations to depositors and other creditors. Here's why the difference matters. Either problem can exist without the other. A bank can be short of reserves on a given day, and still be entirely solvent. That liquidity problem is often solved with short-term borrowing. And a bank can hold ample reserves while being critically undercapitalized. That's a solvency problem, and liquidity alone can't fix it.

So What

Implications, and the Model's Limits

What does this mean for a business? The central implication is that credit availability moves with bank willingness to lend, not just with policy. A business seeking a loan is affected by the broad monetary environment, and by where we are in the business cycle. But it's also affected by the lending posture of the specific banks it approaches. That posture reflects how much in excess reserves those banks choose to hold. And how creditworthy they judge the pool of applicants, including the business itself, at that point in the cycle. So a business's own financial position interacts with banking conditions, in deciding what credit it can actually get. One honest caveat about everything in this section. The simple multiplier model is a teaching device. It's a simplification of how modern banking works. Real banks manage lending, reserves, and capital at the same time, against many requirements and their own risk practices. The model's value is in making deposit creation visible. It doesn't predict the expansion that will actually occur.

Case Vignette

Reserves Without Loans

Ingrid owns a mid-sized construction firm. This is a composite case, constructed for instruction. She wants a loan for new equipment. The news says the banking system is holding unusually large reserves. So she expects credit to be readily available. Instead, her application meets caution, and is finally declined. Her loan officer explains, without discussing any other applicant, that the bank has become more conservative in this downturn. It's holding more than the required reserves. Not because it can't lend, but because it judges fewer applicants creditworthy. And demand for borrowing from qualified applicants has fallen, as businesses grow more cautious. Ingrid's need for the equipment is genuine. But the lending environment is shaped by conditions well beyond her control. No amount of explaining her firm's soundness fully overcomes a system-wide shift toward caution. With her financial adviser, she reaches a clear conclusion. Ample reserves don't translate mechanically into available credit. In a downturn, the binding constraint is willing lending and confident, qualified borrowing, not the quantity of reserves. So she'll plan her firm's financing timeline with that reality in mind.

About Business Essentials at UPI Study

Business Essentials (Business 100) is a self-paced online course of 105 video lessons in 24 chapters, from the business environment, economics and global markets to ownership, management, leadership, operations, people, marketing, accounting, finance and banking. It carries a NCCRS credit recommendation for 3 semester credits.

Every lesson transcript is free on pages like this one, and the videos are free with a free UPI Study account. Enrolling adds a practice quiz after each lesson, the graded work and final exam that earn the credit, lifetime access, and an official transcript on completion. UPI Study has helped over 130,000 students with college credits. ACE and NCCRS have over 2,100 cooperating colleges that will consider accepting credits; the final decision is with the universities.

Compare: Business Essentials vs Principles of Management

Why take it here

Why students take Business Essentials with UPI Study

How a business works, end to endBusiness Essentials is a survey of how companies work: economic systems, global trade, forms of ownership, management and leadership, operations, human resources, marketing, accounting, finance and the banking system. It is a common first course in business, management and accounting degrees.
Credit at a fraction of the priceThe same 3 credits can cost $750 or more at a US college. Here it is one payment, self-paced, with lifetime access.
Finish your degree soonerTransfer credits reduce the courses you still owe, so you can graduate earlier or lighten a heavy semester.
Strengthen an applicationA completed college-level course on an official transcript shows admissions and scholarship committees you can do the work.
Study on your own scheduleNo start dates, no deadlines. Watch the lessons, practice, and take the final when you are ready.
130,000+students helped with college creditsACE and NCCRS have over 2,100 cooperating colleges that will consider accepting credits; the final decision is with the universities.

Where the credit goes

Universities that work with NCCRS

Business Essentials carries a NCCRS credit recommendation. These universities work with NCCRS; some are UPI Study's signed partners. ACE and NCCRS have over 2,100 cooperating colleges that will consider accepting credits; the final decision is with the universities.

Find my college → Not listed? Ask Athena in the corner of this page, or book a 15-minute call.

FAQ

Questions students ask us

About Money and the Multiplier Effect: How Reserve Ratios Work and Why They Matter

How do banks create money?
Banks create money when they lend. Under fractional reserve banking, a bank holds only a fraction of its deposits as reserves. When it makes a loan, it usually credits the borrower's deposit account rather than handing over cash or passing along another depositor's funds, so a new deposit appears that did not exist before. When that money is spent and redeposited, the receiving bank can lend part of it again.
How do you calculate the deposit multiplier?
The deposit multiplier equals 1 divided by the reserve ratio, expressed as a decimal. With a 10 percent ratio it is 1 / 0.10 = 10, so a $1,000 deposit can support at most $10,000 of total deposits. The new deposits run $1,000, $900, $810, $729, and about $656, passing $4,095 after five rounds. A lower reserve ratio gives a larger multiplier and a higher ratio a smaller one.
Why is the real money multiplier smaller than the theoretical one?
Three factors keep real deposit expansion below the theoretical maximum. Currency held outside banks cannot support another round of lending. Excess reserves, held beyond requirements out of caution or weak loan demand, reduce lending. Most fundamentally, banks need willing, creditworthy borrowers; in a downturn fewer businesses seek loans and fewer applicants qualify, so ample reserves do not automatically mean more credit.
What is the difference between reserve requirements and capital requirements?
Reserve requirements concern liquidity: whether a bank has enough readily available funds to meet withdrawals and settle payments. Capital requirements concern solvency: whether the bank's own resources from owners and retained earnings can absorb losses on loans and assets. A bank can be short of reserves for a day yet solvent, or hold ample reserves while badly undercapitalized. The Federal Reserve cut US reserve requirement ratios to zero in March 2020.

About the Business Essentials course

How many college credits is Business Essentials?
Business Essentials (Business 100) carries a NCCRS credit recommendation for 3 semester credits. ACE and NCCRS have over 2,100 cooperating colleges that will consider accepting credits; the final decision is with the universities.
How much does Business Essentials cost and what is included?
$250, paid once, with lifetime access: all 105 video lessons, a practice quiz after each, the graded work and final exam, and an official transcript when you finish. Students who want several courses choose UPI Study PRO instead.
Which universities accept UPI Study credits?
UPI Study has signed partner agreements with universities such as Thomas Edison State University, University of the People and Charter Oak State College, and works with universities such as Penn State, SNHU and SUNY. ACE and NCCRS have over 2,100 cooperating colleges that will consider accepting credits; the final decision is with the universities. Use "Find my college" on this page to check yours.
How long does Business Essentials take?
It is self-paced with no deadlines. The 105 lessons total about 24 hours of video; most students add reading and practice time and finish in a few weeks to a few months, on their own schedule.
How are the exams done?
Quizzes and assignments are online in the course. The final exam is taken online with proctoring; a person on the UPI Study team checks assignments, usually within two days.
How do my credits reach my college?
When the course shows 100% complete, request the official transcript from your dashboard. It is sent to the college you name, and you can send it to more than one. Check your college first with "Find my college" on this page, or ask Athena.

Ready for the full course? Earn 3 credits in Business Essentials.

105 video lessons, a quiz after each one, and the graded work that earns the credit. Recommended for credit by NCCRS.

Business Essentials
3 credits · NCCRS
Enroll →