DEMAND

Class Management and Homework Instructions

• If assignments are not completed, they must be finished by the end of the class.

• New assignments will be given during this class related to demand and supply concepts.

Demand Theory Overview

• We discussed the law of demand: the quantity demanded and the price have an inverse relationship.

• The demand curve can be referred to as a demand line; the main distinction is that a curve may depict changes in slope, whereas a line has a constant slope.

Demand Curve Characteristics

• Typically downward sloping.

• Designated as either 'D' or additional notations such as 'D1', 'D2', 'D3' for multiple graphs.

Variables in Demand Curves

• Quantity is represented by lowercase 'q'.

• Price is represented by lowercase 'p'.

Movement Along the Demand Curve

• Price changes induce movement along the demand curve:

  • A price increase to $p<em>3$ results in a decrease in quantity to $q</em>3$.

  • A price decrease to $p<em>2$ increases quantity to $q</em>2$.

Concept of Shifts

• Demand shifts occur due to factors beyond the price of the good itself:

  • For example, changes in consumer preferences, number of buyers, or external economic conditions.

  • An increase in demand is represented as a rightward shift from $D<em>1$ to $D</em>{1'}$, denoting a rise in quantity demanded at every price point.

Factors Influencing Demand

• Number of buyers in the market can increase or decrease demand.

• Example: Increased health awareness regarding sugar in lattes can decrease demand leading to a leftward shift in the demand curve.

Concepts of Complementary and Substitute Goods

• goods that are consumed together are termed "complements" (e.g., tires and gas).

  • If the price of gas rises, demand for tires decreases due to the reduced need for tires when gas becomes more expensive.

• Substitutes are goods that can replace each other (e.g., Coke and Pepsi).

  • A rise in Coke's price will lead to an increase in the demand for Pepsi.

Normal Goods vs. Inferior Goods

• Normal Goods: Show a positive relationship between income and quantity demanded.

  • Example: Desktop computers, where an increase in consumer income results in an increase in demand.

• Inferior Goods: Demand decreases as income rises and increases as income falls.

Perceptions of Supply and Demand Interaction

• Supply does not determine demand, but is independently affected by it.

• Understanding that demand works based on consumer behavior is crucial even for those studying marketing or business.

Determinants of Supply

• Price or expected price leads to changes in supply decisions which correlate positively.

• Important factors affecting supply:

  • Input costs: Costs of resources needed for production.

  • Technology of production: E.g., innovations that reduce costs.

  • Sellers' expectations: Anticipation of future price changes can affect current supply decisions.

  • Number of sellers: An increase raises market supply, creating more availability.

Law of Supply Insights

• All else equal, higher prices lead to increased quantities supplied, demonstrating a direct relationship between price and supply.

• Supply curves typically slope upwards due to this positive correlation.

Market Dynamics and Supply Changes

• Changes in variable costs (e.g., if milk prices rise, supply will decrease because producers will sell less at the previous quantities to maintain profit margins).

• Improved technology shifts supply rightward, allowing for increased production efficiencies.

Understanding Profit Maximization

• Profit formula: Profit = Revenue - Costs.

• Revenue depends on the product's price multiplied by the quantity sold.

• Input prices determine how much it costs to produce, and consequently affect supply decisions.

Exam Preparations and Class Strategies

• Understanding the assumptions of perfect competition is vital since it distinguishes many concepts in microeconomics.

• Questions may require identifying whether changes affect a good's supply or its demand, emphasizing the necessity to read questions carefully.

Homework Assignments

• Students were assigned to prepare graphs reflecting changes due to price adjustment related to tax preparation software and shifts in competitive market conditions.

Conclusion

• Discussion emphasized the need for practice in distinguishing price effects, shifts, and movements in curve constructs in demand and supply scenarios.