Quick Summary
- Dynamic markets change every few minutes (stocks) to months (clothing)
- Any shift in demand or supply creates temporary disequilibrium
- When demand > supply → excess demand → prices rise
- When supply > demand → excess supply → prices fall
- Higher prices cause suppliers to extend supply (increase quantity, not shift curve)
- Lower prices cause consumers to extend demand (buy more)
- The 7-step systematic process is essential for exam answers
What Are Dynamic Markets?
Real-world markets are not static. They are constantly changing because consumers' preferences change,
supply shocks happen (weather, wars, pandemics), technology improves, and incomes shift. A market reaching equilibrium
is only a snapshot in time.
Dynamic market: A market in which supply and demand conditions are constantly changing, so equilibrium
is frequently disrupted and re-established.
In some markets, equilibrium shifts within minutes (stock exchanges, foreign currency).
In others, it takes weeks or months (clothing, housing). Understanding this timing helps
you explain real-world price movements.
Disequilibrium: The Temporary Imbalance
When a condition of demand or supply shifts (changes), the market is suddenly out of balance.
At the original price, quantity demanded ≠ quantity supplied. This imbalance is temporary—
market forces (mainly price changes) will push the market back towards equilibrium.
Change in demand or supply condition
↓
Temporary disequilibrium
↓
Price moves to clear excess demand or supply
↓
New equilibrium established
Critical distinction: A shift in demand/supply (the curve moves) is different
from an extension/contraction (movement along the curve). When demand shifts right, price rises.
The higher price then causes suppliers to extend supply (move along the supply curve). The
supply curve itself does not shift. Examiners mark this distinction heavily.
The Four Price-Change Scenarios
Every price change in an exam question will fit one of these four scenarios. Master the pattern for each,
and you can handle any market.
Scenario 1: Demand Increases → Price Rises
Real Example: Covid Desk Demand
During 2020 lockdowns, millions of people worked from home for the first time. Suddenly, demand for home office desks
skyrocketed. Supply couldn't keep up. What happened to the price?
- The trigger: Change in taste/preference. People wanted to set up comfortable home offices.
- The shift: Demand for desks moves right (D₁ → D₂).
- At the original price: Quantity demanded now exceeds quantity supplied. Excess demand (shortage) exists.
- Price response: Sellers see queues and empty shelves. They raise prices.
- Movement along curves: The higher price causes suppliers to extend supply (quantity supplied increases along S). The higher price causes some consumers to contract demand (quantity demanded decreases along D₂).
- New equilibrium: At P₂Q₂, where the new demand curve (D₂) meets the unchanged supply curve (S).