Why do we need money?

The short answer

Money makes it easier to exchange goods and services, compare values, and save purchasing power for later. Without money, each trade would require both sides to want exactly what the other offers at the same time.

This barter example simplifies how money can make exchange easier. It does not mean that money always arose from barter in human history. Researchers have proposed several explanations for money's origins, including trade, systems of credit and debt, and the role of states.

Three functions of money

• Medium of exchange: a widely accepted way to pay
• Unit of account: a common scale for comparing prices
• Store of value: a way to carry value into the future

For these functions to work, money needs to be widely accepted, portable, divisible, and reasonably durable.

A useful limit to remember

When prices change, the amount of goods a fixed sum can buy also changes. Money is a useful tool, but its purchasing power is not permanently constant.

Source

• Federal Reserve Bank of St. Louis: Functions of Money
• Nicola Ialongo (2024): The introduction of coinage in Europe did not change pre-existing monetary patterns, Frontiers in Human Dynamics
• Mikael Fauvelle (2025): The Trade Theory of Money: External Exchange and the Origins of Money, Journal of Archaeological Method and Theory