Markets & Prices
How markets coordinate millions of decisions and why prices are the most powerful information system ever invented.
The Price System
Prices carry information. A rising price signals that something is scarce or in high demand. A falling price signals surplus. Without anyone planning it, prices coordinate the actions of millions of buyers and sellers — this is Adam Smith's 'invisible hand.'
Types of Markets
Markets range from perfect competition (many sellers, identical products — like wheat) to monopoly (one seller — like railways). In between are monopolistic competition (many sellers, differentiated products — like restaurants) and oligopoly (few sellers — like telecom).
- •Prices are signals that coordinate economic activity
- •Perfect competition leads to the most efficient outcomes
- •Monopolies can charge higher prices due to lack of competition
- •Market failures (externalities, public goods) justify government intervention
💡 Did You Know?
The New York Stock Exchange processes about 6 billion shares per day. Each trade represents a buyer and seller agreeing on a price — the market in action, millions of times per second.