IRSC ECO2013 demand, supply, and equilibrium

Demand, Supply, and Market Equilibrium

Introduction to Market Equilibrium

  • Adam Smith's concept of the "invisible guiding hand" proposes that supply and demand interact to reach equilibrium in markets.

Demand

Law of Demand

  • States that the quantity demanded of a good is inversely related to its price.

  • Holding other factors constant:

    • Quantity demanded rises as price falls.

    • Quantity demanded falls as price rises.

  • Changes in price lead to changes in consumer purchasing behavior.

Demand Curve

  • Definition: A graphical representation of the relationship between price and quantity demanded.

  • Characteristics:

    • Demand curve is downward sloping; as prices rise, quantity demanded decreases.

Example Demand Table (corn):

Price (P)

Quantity Demanded (Q)

$1.00

9

$2.00

8

$4.00

6

$6.00

4

$8.00

2

Individual and Market Demand Curves

  • Market demand is the summation of individual demands.

  • Individual demand curves can be combined to form a market demand curve.

    • Example: Combining Alice, Bruce, and Carmen's demands for corn.

Shifts in Demand vs. Movements Along a Demand Curve

Key Definitions

  • Quantity Demanded: Specific amount demanded at a specific price.

  • Demand: Schedule of quantities demanded at various prices (entire curve).

Changes in Demand

  • Movements along the demand curve occur due to price changes.

  • Shifts in demand occur due to:

    • Changes in tastes, income, number of buyers, prices of related goods, and expectations.

Determinants of Demand

  • Factors that cause shifts in the demand curve:

    1. Tastes and preferences

    2. Number of buyers

    3. Consumer income

    4. Taxes and subsidies

    5. Expectations about future prices

    6. Prices of related goods (substitutes and complements).

Supply

Law of Supply

  • The quantity of a good supplied is directly related to its price:

    • Quantity supplied rises as price rises.

    • Quantity supplied falls as price falls.

Supply Curve

  • Definition: Graphical representation of the relationship between price and quantity supplied.

  • Characteristics: Supply curve is upward sloping.

Individual and Market Supply Curves

  • Market supply results from summation of individual supplies.

Shifts in Supply vs. Movements Along a Supply Curve

Key Definitions

  • Quantity Supplied: Specific amount supplied at a specific price.

  • Supply: Schedule of quantities supplied at various prices (entire curve).

Changes in Supply

  • A change in price leads to a movement along the supply curve.

  • Non-price changes lead to shifts in the supply curve.

Determinants of Supply

  • Factors that shift the supply curve:

    1. Price of inputs (resources)

    2. Technology advancements

    3. Producer expectations

    4. Taxes and subsidies

    5. Number of sellers

    6. Price change in related goods.

Market Equilibrium

Definition of Equilibrium

  • Equilibrium occurs when quantity supplied equals quantity demanded (intersection of supply and demand curves).

  • Equilibrium Price: Price at which supply equals demand.

  • Equilibrium Quantity: Quantity bought and sold at equilibrium price.

Effects of Surplus and Shortage

  • Surplus: Quantity supplied exceeds quantity demanded, leading to price adjustments.

  • Shortage: Quantity demanded exceeds quantity supplied, causing price increases.

Efficiency in Market Forces

  • Productive Efficiency: Producing goods in the least costly way.

  • Allocative Efficiency: Producing the right mix of goods valued by society.

Changes in Market Equilibrium

Impact of Demand Changes

  • An increase in demand leads to a higher equilibrium price and quantity.

  • A decrease in demand results in lower equilibrium price and quantity.

Impact of Supply Changes

  • An increase in supply leads to a lower equilibrium price and higher quantity.

  • A decrease in supply results in higher equilibrium price and lower quantity.

Applications of Supply and Demand Concepts

  • Real-world examples of shifts in demand and supply affecting equilibrium.

  • Analyze current market scenarios such as price changes in common goods like cigarettes, oil, and food items.

Conclusion

  • Understanding the laws of supply and demand, their determinants, and how they interact in the market is essential for grasping economic concepts.