Transcript Ch 3
3 C HAPTE R Individual Markets: Demand & Supply • What is a “market” ? Buyers or Demanders Sellers or Suppliers Good or Service Price Markets Defined A market is an institution or mechanism that brings together buyers (demanders) and sellers (suppliers) of particular goods and services. • A market may be local, national, or international in scope. • Some markets are highly personal, face-to-face exchanges; others are impersonal and remote. – A product market involves goods and services. – A resource market involves factors of production What is Demand? • Assume the following: Price of the good (KD) Quantity of the good (units) Possible Prices 5 10 3 20 4 35 2 55 1 80 In specified time period Various amounts Graphing Demand P Qd 5 10 4 20 3 35 2 55 1 80 P 5 4 3 2 1 10 20 30 40 50 60 70 80 Qd Graphing Demand P Qd 5 10 4 20 3 35 2 55 1 80 P 5 4 3 2 1 10 20 30 40 50 60 70 80 Qd Demand Demand is a schedule that shows the various amounts of a product that consumers are willing and able to buy at each specific price in a series of possible prices during a specified time period. • The schedule shows how much buyers are willing and able to purchase at five possible prices. • To be meaningful, the demand schedule must have a period of time associated with it. Law of demand • Law of demand “other things being equal, as price increases, the corresponding quantity demanded falls”. • Law of demand restated, “there is an inverse relationship between price and quantity demanded”. • Note the “other-things-equal” assumption refers to consumer income and tastes, prices of related goods, and other things besides the price of the product being discussed. The demand curve 1. Illustrates the inverse relationship between price and quantity. 2. The downward slope indicates lower quantity at higher price and higher quantity at lower price, reflecting the Law of Demand. Individual versus market demand 1. Transition from an individual to a market demand schedule is accomplished by summing individual quantities at various price levels. 2. Market curve is horizontal sum of individual curves. P P 10KD D1 5 P DM D2 Q d1 Consumer (1): at price (10) demands (5) units 8 Q d2 13 Q dM Consumer (2): at Market Demand: price (10) demands at price (10) the (8) units demand is (8) units Changes in Demand • Recall: as price changes, quantity demanded changes: P 10KD Change in prices of the good will always lead to changes in quantity demanded! D 7KD 5 9 Qd As price falls from 10 to 7, Qd increases from (5) to (9) units This is shown by a movement along the demand curve Recall: inverse relationship between P and Qd Determinants of demand This is what we mean by “other things”: a. Tastes favorable change leads to an increase in demand; unfavorable change to a decrease. b. Number of buyers more buyers lead to an increase in demand; fewer buyers lead to a decrease. c. Income more leads to an increase in demand; less leads to a decrease in demand for normal goods. (The rare case of goods whose demand varies inversely with income is called inferior goods). d. i. Prices of related goods Substitute goods (those that can be used in place of each other): The price of the substitute good and demand for the other good are directly related. If the price of Coke rises (because of a supply decrease), demand for Pepsi should increase. ii. Complementary goods (those that are used together like tennis balls and rackets): When goods are complements, there is an inverse relationship between the price of one and the demand for the other. e. Expectations consumer views about future prices, product availability, and income can shift demand. • Changes in determinants of demand will shift the demand curve! P Increase in demand decrease in demand Qd Note that prices are CONSTANT A summary of what can cause an increase in demand. a. Favorable change in consumer tastes. b.Increase in the number of buyers. c. Rising income if product is a normal good. d.Falling incomes if product is an inferior good. e. Increase in the price of a substitute good. f. Decrease in the price of a complementary good. g.Consumer expectation of higher prices or incomes in the future. A summary of what can cause a decrease in demand. a. b. c. d. e. f. g. Unfavorable change in consumer tastes. Decrease in number of buyers. Falling income if product is a normal good. Rising income if product is an inferior good. Decrease in price of a substitute good. Increase in price of a complementary good. Consumers expectation of lower prices or incomes in the future. G. Review the distinction between a change in quantity demanded caused by price change and a change in demand caused by change in determinants. Supply • Supply is a schedule that shows amounts of a product a producer is willing and able to produce and sell at each specific price in a series of possible prices during a specified time period. • A schedule shows what quantities will be offered at various prices or what price will be required to induce various quantities to be offered. Law of supply. • Law of supply “producers will produce and sell more of their product at a high price than at a low price”. • Law of supply restated “There is a direct relationship between price and quantity supplied”. Explanation: Given product costs, a higher price means greater profits and thus an incentive to increase the quantity supplied. Supply Schedule P Qs 5 60 4 50 3 35 2 20 1 5 Various quantities At different prices Supply Schedule P P Qs 5 60 4 50 3 35 2 20 1 5 5 1 4 3 2 1 10 20 30 40 50 60 QS Changes in Qs • Only changes in P will lead to changes in QS • This is a movement along the S curve from one point to the other. • Note that the S curve remains unchanged. P S New as P increases As P increases Qs increases Qs P S New as P decreases As P increases Qs increases Qs Determinants of supply: A change in any of the supply determinants causes a change in supply and a shift in the supply curve. An increase in supply involves a rightward shift, and a decrease in supply involves a leftward shift. Six basic determinants of supply, other than price: a. Resource prices: a rise in resource prices will cause a decrease in supply or leftward shift in supply curve; a decrease in resource prices will cause an increase in supply or rightward shift in the supply curve. b. Technology A technological improvement means more efficient production and lower costs, so an increase in supply or rightward shift in the curve results. c. Taxes and subsidies A business tax is treated as a cost, so decreases supply; a subsidy lowers cost of production, so increases supply. d. Prices of related goods If the price of substitute production good rises, producers might shift production toward the higherpriced good, causing a decrease in supply of the original good. e. Expectations Expectations about the future price of a product can cause producers to increase or decrease current supply. f. Number of sellers Generally, the larger the number of sellers the greater the supply. Changes in S determinants: Shifts in S P 5 4 Increase in Supply S S’ 3 2 1 o 10 20 30 40 50 60 70 80 Q Changes in S determinants: Shifts in S P 5 S S’ 4 3 2 decrease in Supply 1 o 10 20 30 40 50 60 70 80 Q Market Equilibrium • Market Equilibrium: where quantity supplied equals the quantity demanded. • This is: Qs=Qd At PE Recall from D and S tables: P Qd Qs 5 10 60 4 20 50 3 35 35 2 50 20 1 80 5 If P=3, then Qs = Qd there is no surplus (nor shortage) ! Recall from D and S tables: P Qd Qs 5 10 60 4 20 50 3 35 35 2 50 20 1 80 5 This is the market Equilibrium for our good The rationing function of prices is the ability of competitive forces of supply and demand to establish a price where buying and selling decisions are coordinated. MARKET DEMAND & SUPPLY P S 5 4 Market Clearing Equilibrium 3 2 1 o D 2 4 6 78 10 12 14 16 Q MARKET DEMAND & SUPPLY P 5 Surplus S At a 4 price 4 more is being 3 supplied than demanded 2 1 o D 2 4 4 6 78 10 12 14 16 Q MARKET DEMAND & SUPPLY P S 5 At a 2 price 4 more is being 3 demanded than supplied 2 Shortage 1 o D 2 4 6 78 101112 14 16 Q MARKET DEMAND & SUPPLY P 5 Surplus S 4 3 2 Shortage 1 o D 2 4 6 78 101112 14 16 Quantity of Corn Q Application: Government-Set Prices (Ceilings and Floors) Government-set prices prevent the market from reaching the equilibrium price and quantity. A. Price ceilings. • The maximum legal price a seller may charge, typically placed below equilibrium. • Shortages result as quantity demanded exceeds quantity supplied. • Examples: Rent controls and gasoline price controls B. Price floors. • The minimum legal price a seller may charge, typically placed below equilibrium. • Surpluses result as quantity supplied exceeds quantity demanded. • Examples: Minimum wage, farm price supports Note: The federal minimum wage, for example, will be below equilibrium in some labor markets (large cities). In that case the price floor has no effect.