What Is Money?

Module 1 of Foundations

Why This Matters

Before we can understand cryptocurrency, we need to understand money itself. This isn't as obvious as it seems. Ask ten people "what is money?" and you'll get ten different answers - most of them incomplete.

Understanding money deeply will help you:

• Evaluate whether Bitcoin/crypto "is real money"
• Understand why certain design decisions were made
• Recognize what problems crypto is actually solving
• Think clearly about monetary policy debates

The Origin Story: Before Money

Imagine you're a farmer with extra wheat. You need shoes. The shoemaker needs meat, not wheat. The butcher needs tools. The toolmaker needs... wheat!

This is the coincidence of wants problem. For barter to work, you need to find someone who:

1. Has what you want
2. Wants what you have
3. At the same time
4. In the right quantities

This is incredibly inefficient. Anthropologists estimate barter economies severely limited trade and specialization.

Money as a Solution

Money solves this by being an intermediary good - something everyone accepts, not because they want it directly, but because they know others will accept it.

Now the farmer can:

1. Sell wheat → get money
2. Use money → buy shoes

The shoemaker doesn't need to want wheat. They just need to want money (which everyone does, because everyone accepts it).

Key Insight

Money's value comes from a coordination game. It works because everyone believes everyone else will accept it. This is a self-fulfilling belief.

The Three Functions of Money

Economists identify three core functions:

1. Medium of Exchange

Money is what you use to buy things. This is the "solve the barter problem" function.

Requirements:

• Widely accepted
• Easy to transact with
• Divisible (can make change)

2. Store of Value

Money lets you save purchasing power for later. Earn today, spend tomorrow.

Requirements:

• Doesn't decay or spoil
• Maintains value over time
• Scarcity (can't be created arbitrarily)

3. Unit of Account

Money is how we measure and compare value. "This costs $50" is meaningful because we price everything in dollars.

Requirements:

• Stable value (so prices are meaningful)
• Widely understood
• Divisible into standard units

The Tension

These three functions can conflict:

• A volatile asset might be a great store of value long-term but terrible unit of account
• Something widely accepted (medium of exchange) might inflate away (poor store of value)

Bitcoin enthusiasts and critics often talk past each other because they weight these functions differently.

Properties of Good Money

Throughout history, certain things have been used as money: shells, beads, salt, cattle, precious metals, paper, digital entries. What makes something good money?

1. Scarcity

Cannot be easily created. If anyone could make more, it would lose value.

• Gold: Hard to mine
• Dollars: Controlled by Federal Reserve
• Bitcoin: Capped at 21 million, enforced by code

2. Durability

Doesn't decay, break, or spoil.

• Cattle: Poor (they die)
• Gold: Excellent (lasts forever)
• Digital: Perfect (information doesn't decay)

3. Divisibility

Can be split into smaller units for small purchases.

• Real estate: Poor (can't buy coffee with 0.00001 houses)
• Gold: Good (can be divided, though impractical)
• Bitcoin: Excellent (divisible to 8 decimal places)

4. Portability

Easy to move and transport.

• Gold: Poor for large amounts
• Paper money: Good
• Digital: Excellent

5. Fungibility

Each unit is interchangeable with any other.

• Diamonds: Poor (each is unique)
• Dollars: Excellent (any dollar equals any other dollar)
• Bitcoin: Mostly good (but blockchain history creates some complications)

6. Verifiability

Easy to confirm it's real, not counterfeit.

• Gold: Moderate (requires expertise/testing)
• Paper: Moderate (counterfeit detection)
• Bitcoin: Excellent (cryptographically verifiable)

The Evolution of Money

Stage 1: Commodity Money

The money is the valuable thing.

• Examples: Gold, silver, salt, shells
• Advantage: Intrinsic value
• Disadvantage: Heavy, hard to transport and divide

Stage 2: Representative Money

Paper that represents a claim on something valuable.

• Examples: Gold-backed dollars (pre-1971)
• Advantage: Portable, divisible
• Disadvantage: Requires trust in the issuer

Stage 3: Fiat Money

Money by government decree, backed by nothing physical.

• Examples: Modern USD, EUR, all major currencies
• Advantage: Flexible monetary policy
• Disadvantage: Can be inflated, requires trust in government

Stage 4: Digital/Crypto Money (?)

Money as pure information, governed by code.

• Examples: Bitcoin, Ethereum
• Advantage: Programmable, trustless, borderless
• Disadvantage: Volatility, complexity, adoption challenges

The Trust Problem

All money systems require trust somewhere:

The Bitcoin Proposition

Bitcoin's innovation wasn't eliminating trust entirely - it was changing what you need to trust:

• Instead of trusting people/institutions → trust mathematics
• Instead of trusting promises → trust code that executes deterministically
• Instead of trusting a single party → trust a decentralized network

Whether this is "better" depends on your beliefs about math vs institutions.

Why Digital Money Is Hard

This is crucial to understand before we discuss blockchain.

Physical money solves double-spending automatically

If I hand you a $20 bill, I no longer have it. The physical nature prevents me from spending it twice.

Digital information can be copied infinitely

If I send you a digital file, I still have a copy. What stops me from sending the same "digital dollar" to ten different people?

Pre-Bitcoin solutions required trusted intermediaries

• Banks maintain ledgers saying who owns what
• When you "send" money, the bank updates its database
• The bank prevents double-spending by being the single source of truth

The problem with intermediaries

• Single point of failure
• Can censor transactions
• Can be hacked
• Can be pressured by governments
• Charge fees
• Require permission to use

The Bitcoin question

Can we create digital money that prevents double-spending WITHOUT a trusted intermediary?

This is what Satoshi Nakamoto solved in 2008. Understanding why this was hard and how it was solved is the key to understanding blockchain.

Key Takeaways

1. Money is a coordination game - it works because we all agree it works
2. Money has three functions - medium of exchange, store of value, unit of account
3. Good money has specific properties - scarcity, durability, divisibility, portability, fungibility, verifiability
4. All money requires trust - the question is what you're trusting
5. Digital money has unique challenges - specifically, the double-spend problem
6. Bitcoin's innovation was solving double-spend without trusted intermediaries

Questions to Consider

Before moving on, think about:

1. Is your national currency good money? How does it score on each property?
2. Why do you think gold was used as money for thousands of years?
3. What are the tradeoffs between trusting institutions vs trusting code?
4. Can you think of situations where double-spending actually happens today?