Lesson preview · General Equilibrium

From Partial to General Equilibrium

~5 min · Free to read

Moving from partial to general equilibrium requires a conceptual leap. Instead of holding “other things equal,” we let everything adjust. Leon Walras formalized this: a general equilibrium is a set of prices such that every market clears simultaneously. This is called Walrasian equilibrium.

Key Term

Walras' Law

Walras’ Law states that if all markets but one are in equilibrium, the last market must also be in equilibrium. In an economy with n markets, you only need n-1 equilibrium conditions — the nth is automatically satisfied. This is because every purchase is also a sale: the total value of excess demands across all markets must sum to zero.

Walras’ Law: the total value of excess demand across all markets sums to zero

Walras’ Law has a powerful implication: if you observe equilibrium in every market except one, the last market must also clear. Every dollar spent in one market comes from income earned in another. The circular flow of income guarantees that excess demand in one market is matched by excess supply elsewhere.

Worked Example

An economy has 3 goods. At current prices, Good 1 has excess demand of 50 dollars, Good 2 has excess supply of 30 dollars. What is the excess demand for Good 3?

Interactive — Walras’ Law in Action
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Bars showing the value of excess demand in four markets.

Check yourself · no marks

Why does general equilibrium analysis only need n-1 independent equations for n markets?

Commit to one first. Guessing and being wrong beats reading the answer cold.

Practice · 1 / 4

From partial to general equilibrium:

Walras’ Law states that:

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