Market Equilibrium Notes

Market Equilibrium

Demand

  • Law of Demand: Price and quantity demanded move in opposite directions.
    • As price goes up, quantity demanded goes down.
    • As price goes down, quantity demanded goes up.
  • Substitution Effect: Consumers switch to cheaper alternatives when a price increases.
  • Income Effect: Price changes affect consumers' feeling of wealth, altering consumption.
  • Normal Good: Demand increases with income, decreases when income decreases.
  • Inferior Good: Demand decreases with income, increases when income decreases.
  • Substitutes: Increase in the price of one good increases demand for the other.
  • Complements: Increase in the price of one good decreases demand for the other.
  • Shift of the Demand Curve: Change in the amount people are willing and able to buy at every price.
  • Factors that shift the demand curve:
    • Tastes and preferences
    • Income
    • Prices of related goods
    • Expectations
    • Number of buyers
  • Change in Quantity Demanded: Movement along the demand curve due to a price change.

Supply

  • Law of Supply: An increase in the price of a good leads to an increase in the quantity supplied.
  • Supply Schedule: A table listing the quantity of a good that will be supplied at specified prices.
  • Supply Curve: A graphical representation of the supply schedule.
  • Perfect Competition: Many firms selling identical goods, free entry and exit, full information.
  • Shift of the Supply Curve: Change in the quantity supplied at every price.
  • Factors that shift the supply curve:
    * Cost of inputs
    * Government policies (taxes, regulations, subsidies)
    * Number of firms
    * Technological change
    * Natural disasters and weather
    * Expectations about future prices
  • Mnemonic: "P.I.G. T.O.E.S"
    • Productivity
    • Inputs
    • Government Actions
    • Technology
    • Outputs
    • Expectations
    • Size of Industry

Supply and Demand Together

  • Equilibrium: Quantity supplied equals quantity demanded.
  • Market price adjusts to equilibrium through market forces.
  • Excess Demand (Shortage): Quantity demanded exceeds quantity supplied.
  • Excess Supply (Surplus): Quantity supplied exceeds quantity demanded.
  • Changes in supply or demand affect equilibrium price and quantity.
  • Increase in demand: higher equilibrium price and quantity.
  • Increase in supply: lower equilibrium price, higher equilibrium quantity.
  • Decrease in demand: lower price and quantity.
  • Decrease in supply: higher price and lower quantity.
  • BITER:
    * Buyers (# of)
    * Income
    * Tastes
    * Expectations
    * Related goods
  • STONER:
    * Subsidies and taxes
    * Technology
    * Other goods
    * Number of sellers
    * Expectations
    * Resource costs