# Role of Prices Economics Koehn/Molter. Review A demand schedule shows: – How much consumers are willing to buy a various prices. A supply schedule shows:

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Role of Prices Economics Koehn/Molter

Review A demand schedule shows: – How much consumers are willing to buy a various prices. A supply schedule shows: – How much sellers are willing to sell at various prices. Comparing these schedules should allow us to find common ground for the two sides of the market.

Market Equilibrium The point at which quantity demanded and quantity supplied are equal is called EQUILIBRIUM. This can only occur when Quantity demand (QD) = Quantity supplied (QS)

Examples Quantity demanded = Quantity supplied occurs where the demand curve intersects the supply curve. This will determine the equilibrium price and quantity. Equilibrium price = \$5.00 and 5,000 pounds of coffee are bought and sold at that price

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CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND P Q Supply and Demand Together D S Equilibrium: P has reached the level where quantity supplied equals quantity demanded

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND D S P Q Equilibrium price: PQDQD QSQS \$0240 1215 21810 315 41220 5925 6630 The price that equates quantity supplied with quantity demanded

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND D S P Q Equilibrium quantity: PQDQD QSQS \$0240 1215 21810 315 41220 5925 6630 The quantity supplied and quantity demanded at the equilibrium price

Quantity demanded = Quantity supplied (occurs when the demand curve intersects the supply curve) This will determine the equilibrium price and quantity.

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND P Q D S Surplus: when quantity supplied is greater than quantity demanded Surplus Example: If P = \$5, then Q D = 9 lattes and Q S = 25 lattes resulting in a surplus of 16 lattes

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND P Q D S Surplus: when quantity supplied is greater than quantity demanded Facing a surplus, sellers try to increase sales by cutting price. This causes Q D to rise Surplus …which reduces the surplus. and Q S to fall…

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND P Q D S Surplus: when quantity supplied is greater than quantity demanded Facing a surplus, sellers try to increase sales by cutting price. This causes Q D to rise and Q S to fall. Surplus Prices continue to fall until market reaches equilibrium.

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND P Q D S Shortage: when quantity demanded is greater than quantity supplied Example: If P = \$1, then Q D = 21 lattes and Q S = 5 lattes resulting in a shortage of 16 lattes Shortage

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND P Q D S Shortage: when quantity demanded is greater than quantity supplied Facing a shortage, sellers raise the price, causing Q D to fall …which reduces the shortage. and Q S to rise, Shortage

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND P Q D S Shortage: when quantity demanded is greater than quantity supplied Facing a shortage, sellers raise the price, causing Q D to fall and Q S to rise. Shortage Prices continue to rise until market reaches equilibrium.

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND Three Steps to Analyzing Changes in Eqm To determine the effects of any event, 1.Decide whether event shifts S curve, D curve, or both. 2.Decide in which direction curve shifts. 3.Use supply-demand diagram to see how the shift changes eqm P and Q. To determine the effects of any event, 1.Decide whether event shifts S curve, D curve, or both. 2.Decide in which direction curve shifts. 3.Use supply-demand diagram to see how the shift changes eqm P and Q.

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND EXAMPLE: The Market for Hybrid Cars P Q D1D1 S1S1 P1P1 Q1Q1 price of hybrid cars quantity of hybrid cars

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND STEP 1: D curve shifts because price of gas affects demand for hybrids. S curve does not shift, because price of gas does not affect cost of producing hybrids. STEP 2: D shifts right because high gas price makes hybrids more attractive relative to other cars. EXAMPLE 1: A Change in Demand EVENT TO BE ANALYZED: Increase in price of gas. P Q D1D1 S1S1 P1P1 Q1Q1 D2D2 P2P2 Q2Q2 STEP 3: The shift causes an increase in price and quantity of hybrid cars.

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND EXAMPLE 1: A Change in Demand P Q D1D1 S1S1 P1P1 Q1Q1 D2D2 P2P2 Q2Q2 Notice: When P rises, producers supply a larger quantity of hybrids, even though the S curve has not shifted. Always be careful to distinguish b/w a shift in a curve and a movement along the curve.

CHAPTER 4 THE MARKET FORCES OF SUPPLY AND DEMAND STEP 1: S curve shifts because event affects cost of production. D curve does not shift, because production technology is not one of the factors that affect demand. STEP 2: S shifts right because event reduces cost, makes production more profitable at any given price. EXAMPLE 2: A Change in Supply P Q D1D1 S1S1 P1P1 Q1Q1 S2S2 P2P2 Q2Q2 EVENT: New technology reduces cost of producing hybrid cars. STEP 3: The shift causes price to fall and quantity to rise.

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES Government Policies That Alter the Private Market Outcome Price controls – Price ceiling: a legal maximum on the price of a good or service. Example: rent control. – Price floor: a legal minimum on the price of a good or service. Example: minimum wage. Taxes – The govt can make buyers or sellers pay a specific amount on each unit bought/sold. We will use the supply/demand model to see how each policy affects the market outcome (the price buyers pay, the price sellers receive, and eqm quantity).

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES EXAMPLE 1: The Market for Apartments Eqm w/o price controls P Q D S Rental price of apts \$800 300 Quantity of apartments

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES How Price Ceilings Affect Market Outcomes A price ceiling above the eqm price is not binding – has no effect on the market outcome. P Q D S \$800 300 Price ceiling \$1000

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES How Price Ceilings Affect Market Outcomes The eqm price (\$800) is above the ceiling and therefore illegal. The ceiling is a binding constraint on the price, causes a shortage. P Q D S \$800 Price ceiling \$500 250 400 shortage

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES How Price Ceilings Affect Market Outcomes In the long run, supply and demand are more price-elastic. So, the shortage is larger. P Q D S \$800 150 Price ceiling \$500 450 shortage

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES Shortages and Rationing With a shortage, sellers must ration the goods among buyers. Some rationing mechanisms: (1) long lines (2) discrimination according to sellers biases These mechanisms are often unfair, and inefficient: the goods do not necessarily go to the buyers who value them most highly. In contrast, when prices are not controlled, the rationing mechanism is efficient (the goods go to the buyers that value them most highly) and impersonal (and thus fair).

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES EXAMPLE 2: The Market for Unskilled Labor Eqm w/o price controls W L D S Wage paid to unskilled workers \$4 500 Quantity of unskilled workers

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES How Price Floors Affect Market Outcomes W L D S \$4 500 Price floor \$3 A price floor below the eqm price is not binding – has no effect on the market outcome.

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES How Price Floors Affect Market Outcomes W L D S \$4 Price floor \$5 The eqm wage (\$4) is below the floor and therefore illegal. The floor is a binding constraint on the wage, causes a surplus (i.e., unemployment). 400 550 labor surplus

CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES Min wage laws do not affect highly skilled workers. They do affect teen workers. Studies: A 10% increase in the min wage raises teen unemployment by 1-3%. The Minimum Wage W L D S \$4 Min. wage \$5 400 550 unemp- loyment

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