教程分析课件

1、1ACE EconomicsLecture 3: Looking at markets using demand and supplyTrinity College Foundation StudiesLecture OutlineWhat is a marketSupply and demand modelBehaviour of buyersBehaviour of sellersInteraction of buyers and sellersWhat causes market prices to change2 mended readingRichard Morris., Econo

2、mics Down Under, VCE Economics, Units 1 and 2, 9th Edition, Jacaranda. Reading for lecture 3: Chapter 1Class notes3What is a market?Markets are places (real or virtual) where buyers and sellers meet to exchange goods and services at agreed prices. Often this process involves some haggling or bargain

3、ing, since buyers want to purchase at low prices and sellers like to receive high prices for what they produce. A feature common to all markets is that there are buyers and sellers who determine prices. 4What is a market?There are some differences in markets, for example:There are open or free marke

4、ts, as well as black markets (e.g. for illegal production like some drugs). Some markets can involve face-to-face contact between consumers and producers at a particular location (e.g. the Queen Victoria Market in Melbourne). Increasingly, however, due to the rapid growth in the Internet and improve

5、ments in munications, those individuals participating in the market never see each other, may live in different countries and may even use different currencies. 5How market prices inform firms and owners of resources what to produce6The Supply and Demand ModelA way to look at how a competitive marke

6、t makes decisions and allocates resources is through the use of demandsupply diagrams. Each diagram represents a market for a particular good (e.g. sunglasses) or a specific service (e.g. live entertainment). These diagrams or graphs are especially useful when analysing the impact of factors affecti

7、ng buyers (i.e. demanders), sellers (i.e. suppliers) and market prices. Let us see what these diagrams look like by first checking out the way buyers and sellers commonly behave in the marketplace. 7Demand the behaviour of buyersDemand refers to what buyers are prepared to pay for a particular quant

8、ity of a good or service.Buyers are prepared to buy a greater quantity of a particular good or service at a low price rather than at a high price. The behaviour of consumers in the market is summed up as the law of demand that is, as the price of a good or service rises, the quantity demanded fallsi

9、f the price falls, the quantity demanded increases. This assumes that all other influences on demand are held constant8Demand Market for cinema ticketsP($)45320204060801001Demand CurveDemand SchedulePriceQuantity demanded01201100280360440520606120Terminology: increase in price decrease in quantity d

10、emanded (movement alongdemand curve).QAB9Demand the behaviour of buyersFor cinema tickets, the demand curve, DD, has a negative slope down and to the right on the graph.A move from point A (40 tickets) to point B (80 tickets) on this demand curve is called an increase in the quantity demanded. It is

11、 caused by a fall in prices (from $4 to $2 per ticket).However, a move from point B (80 tickets) to point A (i.e. 40 tickets) is called a decrease in the quantity demanded and is caused by a rise in the price of tickets (from $2 to $4). This sort of consumer behaviour can be seen in any competitive

12、market, no matter what type of goods or services is involved.10Supply the behaviour of sellersSupply refers to what sellers are prepared to sell at a particular price.Suppliers want to sell more at a high price rather than a low price - because it is more profitable. Seller behaviour in the market i

13、s summarised as the law of supply that is, As the price of a good or service rises the quantity supplied increases,If the price falls the quantity supplied decreases. This assumes that all other influences on supply are held constant11Supply Market for cinema ticketsP45320204060801001Supply CurveSup

14、ply SchedulePriceQuantity supplied00120240360480510061206120Terminology: Increase in price - increase in quantity supplied (movement alongsupply curve)QBA12Supply the behaviour of sellersFor cinema tickets, notice that the supply curve (S-S) has a positive slope up and to the right on the graph. A m

15、ove from point A (40 tickets) to point B (80 tickets) up along this supply curve is called an increase in the quantity supplied and is caused by a rise in the price of tickets (from $2 to $4 per ticket).However, a move from point B (80 tickets) to point A (40 tickets) is called a decrease in the qua

16、ntity supplied and is caused by a fall in the price of tickets (from $4 to $2 per ticket). This sort of behaviour is typical of the supply of all types of goods or services in competitive markets.13Interaction of buyers and sellersThe conflicting behaviour of buyers and sellers results in a need for

17、 compromise.Buyers want to buy at a low price and sellers want to supply at a high price. The solution to this problem is found at the equilibrium price. This is the market price where the quantity demanded (Qd) exactly equals the quantity supplied (Qs). This is called the equilibrium quantity.In th

18、is situation, the market is cleared of any surplus or shortage, and both buyers and sellers are happy to trade at the equilibrium price. 1415Market equilibrium graphical representationP45320204060801001PriceQuantity demandedQuantity supplied01200110020280403606044080520100601206120QSupplyDemandEquil

19、ibrium:Pe = 3; Qe = 60 Interaction of buyers and sellersIn this market, the the equilibrium price (Pe) is $3 and the equilibrium quantity (Qe) is 60 tickets per year. At a market price of $3 the quantity demanded (Qd = 60 tickets) exactly equals the quantity supplied (Qs = 60 tickets). There is no s

20、urplus or shortage, and both buyers and sellers are happy to trade at the equilibrium price of $3. 16Interaction of buyers and sellersWhat happens at prices above equilibrium?At prices above the free equilibrium price (e.g. say $4 per ticket), the market would not be in equilibrium.There would be a

21、surplus (by 40 tickets) because quantity supplied (Qs = 80 tickets) would exceed the quantity demanded (Qd = 40 tickets). Sellers would be unhappy as they are unable to sell all their tickets. In a freely competitive market, prices would automatically fall back towards the equilibrium price ($3 per

22、ticket) Simultaneously, there will be an increase in the quantity demanded and and a decrease in the quantity supplied until the two are equal.1718Interaction of buyers and sellersP45320204060801001PriceQuantity demandedQuantity supplied01200110020280403606044080520100601206120QSupplyDemandInteracti

23、on of buyers and sellersWhat happens at prices below equilibrium?If prices were below the equilibrium price (say $2 per ticket), there would be a shortage (by 40 tickets) because quantity demanded (Qd = 80 tickets) would exceed quantity supplied (Qs = 40 tickets). There would be queues of dissatisfi

24、ed buyers. In a freely competitive market, the price of tickets would soon move upwards towards the equilibrium price ($3 per ticket). Simultaneously there would be a decrease in the quantity demanded and an increase in the quantity supplied until the two were equal.192010. Market equilibrium graphi

25、cal representationP45320204060801001PriceQuantity demandedQuantity supplied01200110020280403606044080520100601206120QSupplyDemandWhat causes market prices to changePrice changes caused by new conditions that shift the whole demand curve or supply curve1) Shift in the demand curve:New conditions of d

26、emand means that buyers will now purchase an increased or decreased quantity than previously at all possible price levels.2) Shift in the supply curve:New conditions of supply means that sellers will now sell an increased or decreased quantity than previously at all possible price levels.21What caus

27、es market prices to changeShifts in the demand curve:When buyers are prepared to purchase more at a given price than previously because of stronger demand conditions, this is called an increase in demand. This is represented as a shift in the demand curve to the right of the original demand curve (a

28、 shift on the graph from D1 to D2).A decrease in demand is represented as a shift in the demand curve to the left of the original demand curve on the graph (from D1 to D0). 2223D2SD1Q2P2Increase in demand:Shift in the demand curve to the right from D1 to D2Equilibrium price increases from P1 to P2Eq

29、uilibrium quantity increases from Q1 to Q2PQQ1P1What causes market prices to change24D0SD1Q2P2Decrease in demand:Shift in the demand curve to the left from D1 to D0Equilibrium price falls from P1 to P2Equilibrium quantity falls from Q1 to Q2PQQ1P1What causes market prices to changeWhat causes market

30、 prices to changeCauses of shifts in the whole demand curve:changes in household echanges in fashions and tastesanticipated future rises or falls in pricechanges in the prices of related goods (substitutes or complementary goods) changes in number of consumers2526What causes market prices to changea

31、) Changes in household e: i) Normal good increase (decrease) in e causes an increase (decrease) in demand. An increase in e means you have more to spend on most goods.ii) Inferior good increase (decrease) in e causes a decrease (increase) in demand. For some goods, like bus rides, as your e increase

32、s more likely to use a car or take taxis and less likely to take the bus.What causes market prices to change2728What causes market prices to changeb) Changes in the prices of related goods:i) Substitutes: two goods that can be used in place of each other, like butter and margarine, and DVD rentals a

33、nd movie tickets. An increase (decrease) in price of a substitute good can cause an increase (decrease) in the demand for the other good.ii) Complements: two goods that are used together, like petrol and cars, and computers and software. An increase (decrease) in price of a complement good can cause

34、 a decrease (increase) in demand for the other good.What causes market prices to change2930What causes market prices to changec) Changes in fashions and tastes:An increase (decrease) in preference for a good causes demand to increase (decrease).d) Anticipated future rises or falls in price:An increa

35、se (decrease) in expected price tomorrow causes an increase (decrease) in demand today.e) Changes in the number of buyers:An increase (decrease) in the number of buyers in a market causes demand to increase (decrease). This may be due to changes in population size and/or age distribution.What causes

36、 market prices to changeShifts in the supply curve:New conditions of supply also alter market prices. An increase in supply (a shift down and to the right in the supply curve) is caused by more favourable conditions for producers (i.e. from S1 to S2).A decrease in supply (a shift up and to the left)

37、 is caused by less favourable supply conditions (i.e. from S1 to S0).3132S2Q2Increase in supply:Shift in the supply curve to the right from S1 to S2Equilibrium price falls from P1 to P2Equilibrium quantity increases from Q1 to Q2PQS1DP2Q1P1What causes market prices to change33S0Decrease in supply:Sh

38、ift in the supply curve to the left from S1 to S0Equilibrium price increases from P1 to P2Equilibrium quantity falls from Q1 to Q2PQS1DP2Q1P1What causes market prices to changeQ2What causes market prices to changeCauses of shifts in the supply curve.changes in the costs of production, such as wages or materials, utilities (e.g. water, power, rates) introduction of a more advanced technologyanticipated future rises or falls in pricechanges in the number of sel