Notes on Law of Demand and Market Equilibrium

Introduction

  • Focus on two fundamental natural laws: the law of demand and the law of supply.
  • These laws are essential for understanding market equilibrium, which is crucial for economic growth.

Market Equilibrium

  • Market equilibrium occurs when consumers' choices meet sellers' choices at an equilibrium price.
  • Businesses aim for equilibrium, not merely to break even, as it signifies effective economic activity.

Consumer Behavior

  • Consumer behavior reflects the law of demand.
  • It centers on utilitarian philosophy, focusing on maximizing happiness through functional properties.
  • The relationship between utility (happiness) and income is significant; higher income generally leads to greater happiness, though real-world applications often differ.

Law of Demand

  • Demand is defined in economics as a function that incorporates both willingness and ability to buy.
  • Key components of demand:
    • Willingness: Desire to purchase a good or service.
    • Ability: Financial capacity to make the purchase.
  • For demand to exist, both willingness and ability must be present.

Inverse Relationship

  • The law of demand posits an inverse relationship between price and quantity demanded:
    • As price decreases, quantity demanded increases.
    • As price increases, quantity demanded decreases.
  • Example: If rice costs 50 pesos per kilo today, and it rises to 150 pesos tomorrow, consumers will demand a lesser quantity due to higher prices.

Assumptions in Demand Analysis

  • Ceteris Paribus: All other factors are held constant to focus on the impact of price changes.
  • An essential concept for analyzing demand in isolation from external influences.

Demand Function and Curve

  • The demand function can be represented mathematically; it is typically in the form of Qd = f(P), where Qd is the quantity demanded and P is the price.
  • Demand curves can be analyzed in three phases:
    1. Immediate run
    2. Short run
    3. Long run
  • The visual representation highlights how quantity demanded reacts to price variations.

Changes in Demand vs. Changes in Quantity Demanded

  • Change in Quantity Demanded: Occurs due to price changes (movement along the demand curve).
  • Change in Demand: Involves shifts of the entire demand curve due to factors other than price, such as:
    • Change in consumer income.
    • Changes in consumer preferences.
    • Price of related goods (substitutes & complements).

Price Elasticity of Demand

  • Elasticity: Describes consumer sensitivity to price changes.
    • Elastic Demand: Significant change in quantity demanded with smaller price changes (e.g., luxury items).
    • Inelastic Demand: Minimal change in quantity demanded despite price changes (e.g., essential goods).
  • Buyer expectations about future prices can influence demand elasticity; expected price increases may prompt immediate purchases.

Non-Price Determinants of Demand

  1. Income: Higher income typically increases demand for superior goods (luxury items) while reducing demand for inferior goods (cheaper alternatives).
  2. Tastes and Preferences: Shifts in consumer preference can increase or decrease demand.
  3. Buyers' Expectations: Anticipation regarding future prices impacts current demand levels.
  4. Price of Related Goods:
    • Substitutes: Increase in substitute goods' prices leads to higher demand for the original good.
    • Complements: Increased prices for complementary goods (like bread and peanut butter) decrease demand for the complementary item.

Conclusion

  • Understanding the law of demand is essential for consumers and businesses.
  • The next focus will be on the law of supply and how both laws contribute to market equilibrium.
  • Practical application of these concepts will involve group scenarios for deeper economic analysis.