Demand, Supply, and Market Equilibrium

Principles of Macroeconomics

Supply and Demand in Markets for Goods and Services

  • Product or Output Markets: Environments where goods and services are exchanged.

  • Input or Factor Markets: Environments where factors of production (labor, capital, land, entrepreneurship, technology) are exchanged.

Demand in Markets for Goods and Services

  • Quantity Demanded (Qd): Amount of a product a household would buy in a given time period at the current market price.

Supply in Markets for Goods and Services

  • Quantity Supplied (Qs): Amount of a product that a firm is willing to offer for sale at a specific price during a given time period.

Determinants of Demand

  • Price and the Law of Demand: Inversely related; as price rises, quantity demanded decreases (and vice versa).

  • Income:

    • Normal Goods: Demand rises when income increases.

    • Inferior Goods: Demand decreases as income increases.

  • Wealth: Net worth (total assets minus liabilities); a stock measure.

  • Expectations: About future prices, income, and wealth.

  • Prices of Other Goods:

    • Substitutes: Goods that can replace others; higher prices of one increase demand for its substitute.

    • Complements: Goods that are consumed together; a price decrease in one increases demand for the other.

  • Tastes and Preferences: Individual preferences affect demand.

Demand Function

  • General representation: Qd = f(Price, Income, Wealth, Expectations, Prices of other goods, Tastes)

  • Demand Curve: Illustrates the relationship between price and quantity demanded holding all else constant.

Changes in Demand vs. Quantity Demanded

  • Movement Along the Curve: Caused by price changes, resulting in changes in quantity demanded.

  • Shift of the Demand Curve: Caused by changes in other determinants (e.g., income or preferences).

Supply in Markets for Goods and Services

  • Supply Function: Qs = f(Price, Price of inputs, Technology, Price of other products)

  • Law of Supply: Directly related; higher prices lead to higher quantities supplied (and vice versa).

Changes in Supply vs. Quantity Supplied

  • Movement Along Supply Curve: Caused by price changes.

  • Shift of Supply Curve: Due to changes in other factors influencing supply.

Market Equilibrium

  • Equilibrium: Occurs when quantity supplied equals quantity demanded (Qs = Qd).

  • Excess Demand (Shortage): Price below equilibrium leads to this condition, creating upward pressure on prices.

  • Excess Supply (Surplus): Price above equilibrium leads to this condition, creating downward pressure on prices.

Price Rationing Mechanism

  • How markets allocate goods when quantity demanded exceeds quantity supplied.

  • Adjustment of Prices: Shortages lead to higher prices, which reduce quantity demanded and increase quantity supplied until equilibrium is reached.

Alternative Rationing Mechanisms

  • Price Ceiling: Limit on how high price can go (set below equilibrium), leading to shortages.

  • Price Floor: Limit on how low prices can go (set above equilibrium), leading to surpluses.

Consequences of Price Ceilings and Floors

  • Price Ceilings: Can lead to queuing, favored customers, ration coupons, and black markets.

  • Price Floors: Often result in excess supply, requiring measures such as government purchasing or production limits.

Tariffs on Imports

  • Effects:

    • Tariff increase leads to higher import prices, negatively affecting consumers but benefiting domestic producers and government revenues.

    • Example: Tariff on oil, and its impact on consumers and domestic producers.

Gains from Trade vs. Losses from Tariffs

  • Economic Efficiency: Loss when tariffs are imposed as they lead to higher consumer prices for domestically produced goods that could have been less costly.

Example Case Studies on Tariffs**

  • Electric Vehicles: Tariff implications on prices and consumer choices.

  • Steel and Aluminum: Jobs created in domestic manufacturing versus cost increases for other sectors.