Market Equilibrium and Market Happenings

Market Equilibrium

Market equilibrium occurs when the quantity demanded (QD) equals the quantity supplied (QS) at a particular price. At this point, there is no tendency for the price to change, and the market clears.

• Equilibrium Price (Pe): The price at which QD = QS.

• Equilibrium Quantity (Qe): The quantity bought and sold at equilibrium price.

• Incentive: If price (P) is above or below Pe, market forces create incentives for buyers and sellers to adjust their behavior, moving the market back toward equilibrium.

• Efficiency: At equilibrium, the allocation of goods is most efficient, maximizing total surplus for market participants.

Formula:

• Equilibrium occurs where:

Example: If the price of apples is above equilibrium, there will be excess supply, leading sellers to lower prices until equilibrium is restored.

Market Happenings

Markets are dynamic and can experience changes due to shifts in demand or supply. These changes create surpluses or shortages, which in turn affect prices and quantities.

• Surplus: Occurs when QS > QD at a given price. Firms compete to sell excess goods, driving the price down.

• Shortage: Occurs when QD > QS at a given price. Consumers compete for limited goods, driving the price up.

• Adjustment Process: Price changes continue until a new equilibrium is reached.

Example: A sudden increase in demand for hand sanitizer creates a shortage, causing prices to rise until supply catches up.

Demand and Supply Shifters

Demand Shifters

Demand shifters are variables that cause the demand curve to shift, changing the quantity demanded at every price.

• Price of Related Goods: Changes in the prices of substitutes or complements affect demand.

• Income: Higher income increases demand for normal goods and decreases demand for inferior goods.

• Population/Demographics: An increase in population generally increases demand.

• Tastes and Preferences: Changes in consumer preferences can shift demand.

• Expectations: If consumers expect prices to rise in the future, current demand may increase.

Graphical Representation:

• Rightward Shift: Increase in demand (D to D').

• Leftward Shift: Decrease in demand (D to D'').

Example: A rise in the price of coffee increases demand for tea (a substitute).

Supply Shifters

Supply shifters are variables that cause the supply curve to shift, changing the quantity supplied at every price.

• Input Prices: Higher input costs decrease supply.

• Technology: Technological improvements increase supply.

• Number of Sellers: More sellers increase market supply.

• Expectations: If producers expect higher future prices, they may decrease current supply.

Graphical Representation:

• Rightward Shift: Increase in supply (S to S').

• Leftward Shift: Decrease in supply (S to S'').

Example: A new technology reduces production costs, shifting the supply curve to the right.

Prices of Related Goods and Services

The relationship between goods affects demand through substitutes and complements.

Formulas:

• For substitutes: If , then

• For complements: If , then

Income and Demand

Income changes affect demand differently for normal and inferior goods.

• Normal Goods: Demand increases as income increases.

• Inferior Goods: Demand decreases as income increases.

Formulas:

• For normal goods: If , then

• For inferior goods: If , then

Example: As income rises, demand for restaurant meals (normal good) increases, while demand for instant noodles (inferior good) decreases.

Population and Demographics

Population size and demographic factors influence market demand.

• Population: An increase in the number of consumers increases demand for most goods and services.

• Demographics: Age, sex, religion, and other demographic factors can shift demand for specific goods.

Example: An aging population increases demand for healthcare services.

Summary Table: Demand and Supply Shifters