Demand and Supply Analysis Notes

Chapter 2: Demand and Supply Analysis

A. Demand Concept

  • Price and Quantity Demanded
    • The relationship between price (P) and quantity demanded (Qd):
    • Inversely related: As P increases, Qd decreases (Law of Demand).
    • Graphically illustrated by a downward-sloping demand curve.
    • Algebraically expressed in a negatively sloped equation.
  • Other Factors Affecting Demand
    1. Consumer's income (Y): Increased income boosts demand for normal goods but decreases for inferior goods.
    2. Prices of substitutes (Ps) and complements (Pc): E.g., higher Coca-Cola prices increase Pepsi demand.
    3. Price expectations: Anticipation of price increases leads to higher current demand.
    4. Number of consumers: An increase in consumer count amplifies demand.
    5. Tastes and preferences: Influenced by factors such as fashion and advertising.
  • Elasticity of Demand
    • Measures responsiveness to price changes:
    • Elastic (Ed > 1): Qd responds strongly to P changes.
    • Inelastic (Ed < 1): Qd responds weakly to P changes.
    • Unitary (Ed = 1): Changes in Qd equal changes in P.

B. Supply Concept

  • Price and Quantity Supplied (Qs)
    • P and Qs are positively related:
    • As P increases, Qs also increases (Law of Supply)
    • Graphically illustrated by an upward-sloping supply curve.
  • Other Factors Affecting Supply
    1. Cost of production: Higher production costs reduce Qs.
    2. Taxes and subsidies: Increased taxes lower supply; subsidies enhance it.
    3. Price expectations: Anticipation of higher prices can reduce immediate supply.
    4. Technology improvements: Can increase supply by reducing production costs.
    5. Number of sellers: More sellers generally increase total supply.

C. Market Equilibrium

  • Equilibrium Price (Pe): Price at which quantity demanded (Qd) equals quantity supplied (Qs).
  • Surplus and Shortage:
    • Surplus occurs when Qs > Qd (above Pe); prices tend to decrease.
    • Shortage occurs when Qd > Qs (below Pe); prices tend to increase.

D. Market Failures

  • Definition: Inefficient allocation of resources, resulting from market distortions (e.g., monopolies, externalities).
  • Causes of Market Failure:
    1. Externalities: Costs or benefits affecting third parties not involved in a transaction.
    2. Public Goods: Non-rivalrous and non-excludable goods, consumed collectively without reducing availability.
    3. Market Control: Power dynamics, either monopolistic (sellers) or monopsonistic (buyers), disrupt fair pricing.
    4. Imperfect Information: Buyers/sellers lack sufficient information, leading to suboptimal economic decisions.
  • Solutions:
    1. Legislation: Government interventions to regulate and correct market behavior.
    2. Price Mechanisms: Altering consumer/producer behaviors through taxes, especially on harmful goods (e.g., tobacco).

Additional Concepts

  1. Demand Schedule & Curve: Detailed tabulated values showing Qd at various prices, and graphical representation.
  2. Calculation of Demand Elasticity:
    • Formula:
      [ Ed = \frac{% \text{ Change in } Qd}{% \text{ Change in } P} ]
    • Interpretation of calculated coefficients for elasticity: Elasticity affecting total revenue dynamics.
  3. Supply Schedule & Equation: Graphical and algebraic representation for analyzing various price points.