Definition, Measurement
& Functions of Money
Explore what money is, why it matters, how we measure the money supply, and the essential functions that make modern economies work.
What Is Money?
Money is any asset that is widely accepted as a medium of exchange in transactions for goods and services. It is not simply cash: money includes anything a society agrees can settle debts and purchase goods.
The Three Functions of Money
Why Money Matters
Without money, economies rely on barter: the direct exchange of goods for goods. Barter requires a double coincidence of wants: both parties must desire exactly what the other has to offer.
Commodity vs Fiat Money
| Commodity Money | Fiat Money | |
|---|---|---|
| Intrinsic Value | Yes: the item has value on its own | No: value comes from government decree |
| Examples | Gold, silver, salt, cattle | U.S. dollar, euro, yen |
| Backing | Backed by the commodity itself | Backed by public trust and legal tender laws |
| Supply Control | Limited by physical supply | Controlled by the central bank |
Properties of Good Money
Measuring the Money Supply
The Federal Reserve tracks the money supply using different measures based on liquidity: how quickly an asset can be converted to cash without losing value.
\( M1 \): The Most Liquid Money
\( M1 \) includes the most liquid forms of money: assets that can be used immediately for transactions without conversion.
\( M2 \): The Broader Measure
\( M2 \) includes everything in \( M1 \) plus near-money assets that are slightly less liquid but easily convertible to cash.
The Liquidity Spectrum
\( M1 \) vs \( M2 \): Key Distinction
| \( M1 \) | \( M2 \) | |
|---|---|---|
| Definition | Most liquid money | \( M1 \) + near-money |
| Includes | Cash, checking, traveler's checks | + Savings, small CDs, money market |
| Can Spend Immediately? | Yes | Usually needs conversion |
| Size (U.S., approx.) | \( \sim\$4.5 \) trillion | \( \sim\$21 \) trillion |
| Fed Uses For | Transaction money tracking | Broader economic analysis |
How to Classify an Asset
Example: Classifying Assets
Jamal has the following assets. Classify each as \( M1 \), \( M2 \) only, or neither:
Example: Trickier Assets
Example: Computing \( M1 \) and \( M2 \)
Given the following data for a hypothetical economy, compute \( M1 \) and \( M2 \):
| Asset | Amount (billions) |
|---|---|
| Currency in circulation | \( \$800 \) |
| Demand deposits | \( \$1{,}200 \) |
| Savings deposits | \( \$2{,}500 \) |
| Small time deposits | \( \$600 \) |
| Money market funds | \( \$400 \) |
Common Mistakes
Question 1 of 5
Which of the following is NOT a function of money?
Question 2 of 5
A \( \$10{,}000 \) balance in a savings account is included in:
Question 3 of 5
Which of the following best explains why credit cards are not considered part of the money supply?
Question 4 of 5
An economy has \( \$600 \) billion in currency, \( \$900 \) billion in demand deposits, \( \$1{,}400 \) billion in savings deposits, and \( \$300 \) billion in small time deposits. What is \( M2 \)?
Question 5 of 5
U.S. dollars are an example of fiat money because they: