The meaning of market equilibrium

Market equilibrium occurs when the quantity supplied equals the quantity demanded at a specific price, creating a stable balance in the market.

Characteristics of market equilibrium

• At this point, the price and quantity remain steady because supply matches demand exactly.
• All goods offered for sale are purchased, clearing the market with no leftovers or shortages.
• In a free market, the interaction between supply and demand sets this equilibrium price and quantity.
• These interactions are known as market forces.
• On a diagram, equilibrium is where the supply curve intersects the demand curve.

When supply and demand do not match, the market enters disequilibrium, leading to imbalances like excess supply or demand.

Excess supply and demand leading to disequilibrium

Disequilibrium happens when supply and demand are unequal, causing either too much supply or too much demand at the current price.

Excess supply

Excess supply arises when the quantity supplied exceeds the quantity demanded. This typically occurs if the price is set above the equilibrium level, causing suppliers to produce more than consumers want to buy, leading to unsold stock.

Excess demand

Excess demand occurs when the quantity demanded exceeds the quantity supplied. This usually happens if the price is set below the equilibrium level, meaning consumers want more than what is available, leading to shortages.

In a free market, these imbalances do not last long due to market forces.

How market forces restore equilibrium

Market forces naturally adjust prices and quantities to eliminate disequilibrium and return the market to balance.

Adjustments in cases of excess supply

• With excess supply, suppliers lower prices to sell off surplus stock.
• As prices fall, demand extends (more buyers enter the market) and supply contracts (fewer suppliers produce at the lower price).
• This continues until supply equals demand at a new equilibrium.

Adjustments in cases of excess demand

• With excess demand, competition among buyers drives prices up.
• As prices rise, demand contracts (some buyers drop out) and supply extends (more suppliers enter to meet demand).
• This process persists until supply matches demand at a new equilibrium.

Changes in equilibrium from shifts in demand or supply

Shifts in the demand or supply curves alter the equilibrium price and quantity, assuming the other curve remains unchanged.

Effects of shifts in the demand curve

• An increase in demand shifts the curve rightward, raising the price and extending supply to form a new equilibrium with higher price and quantity.
• A decrease in demand shifts the curve leftward, lowering the price and contracting supply to create a new equilibrium with lower price and quantity.

Effects of shifts in the supply curve

• An increase in supply shifts the curve rightward, reducing the price and extending demand to establish a new equilibrium with lower price and higher quantity.
• A decrease in supply shifts the curve leftward, increasing the price and contracting demand to set a new equilibrium with higher price and lower quantity.

The role of elasticity and assumptions of the model

Elasticity influences how much the equilibrium changes after a shift, while the model relies on certain assumptions that limit its real-world application.

How elasticity affects the new equilibrium

• Price elasticity of demand and supply determines the extent of changes in price and quantity.
• When demand shifts along an elastic supply curve, the impact is greater on quantity than on price.
• Conversely, with an inelastic supply curve, the shift affects price more than quantity.
• The same applies to supply shifts: elastic demand leads to larger quantity changes, while inelastic demand causes bigger price changes.

Assumptions of the demand and supply model

• Supply and demand operate independently of each other.
• All markets are perfectly competitive, with many buyers and sellers.
• Ceteris paribus applies, meaning all other factors remain constant.
• These assumptions simplify the model for understanding basic principles but reduce its accuracy in complex real-world scenarios.