外文翻译---供给与需求的市场力量

1、.附录AA.1 THE MARKET FORCES OF SUPPLY AND DEMAND When a cold snap hits Florida，the price of orange juice rises in supermarkets throughout the countryWhen the weather turns warm in New England every summer，the price of hotel rooms in the Caribbean plummetsWhen a war breaks out in the Middle East，the pr

2、ice of gasoline in the United States rises，and the price of a used Cadillac fallsWhat do these events have in common? They all show the workings of supply and demand Supply and demand are the two words that economists use most oftenand for good reasonSupply and demand are the forces that make market

3、 economies workThey determine the quantity of each good produced and the price at which it is soldIf you want to know how any event or policy will affect the economy，you must think first about how it will affect supply and demandThis chapter introduces the theory of supply and demandIt considers how

4、 buyers and sellers behave and how they interact with one anotherIt shows how supply and demand determine prices in a market economy and how prices，in turn，allocate the economy's scarce resourcesA.1.1 MARKETS AND COMPETITION The terms supply and demand refer to the behavior of people as they int

5、eract with one another in marketsA market is a group of buyers and sellers of a particular good or serviceThe buyers as a group determine the demand for the product，and the sellers as a group determine the supply of the productBefore discussing how buyers and sellers behave，let's first consider

6、more fully what we mean by a “market” and the various types of markets we observe in the economyA.1.1.1 COMPETITIVE MARKETS Markets take many formsSometimes markets are highly organized，such as the markets for many agricultural commoditiesIn these markets，buyers and sellers meet at a specific time a

7、nd place，where an auctioneer helps set prices and arrange sales More often，markets are less organizedFor example，consider the market for ice cream in a particular townBuyers of ice cream do not meet together at any one timeThe sellers of ice cream are in different locations and offer somewhat differ

8、ent productsThere is no auctioneer calling out the price of ice creamEach seller posts a price for an ice-cream cone，and each buyer decides how much ice cream to buy at each store Even though it is not organized，the group of ice-cream buyers and ice-cream sellers forms a marketEach buyer knows that

9、there are several sellers from which to choose，and each seller is aware that his product is similar to that offered by other sellersThe price of ice cream and the quantity of ice cream sold are not determined by any single buyer or sellerRather，price and quantity are determined by all buyers and sel

10、lers as they interact in the marketplace The market for ice cream，like most markets in the economy，is highly competitiveA competitive market is a market in which there are many buyers and many sellers so that each has a negligible impact on the market priceEach seller of ice cream has limited contro

11、l over the price because other sellers are offering similar productsA seller has little reason to charge less than the going price，and if he or she charges more，buyers will make their purchases elsewhereSimilarly，no single buyer of ice cream can influence the price of ice cream because each buyer pu

12、rchases only a small amountIn this chapter we examine how buyers and sellers interact in competitive marketsWe see how the forces of supply and demand determine both the quantity of the good sold and its priceA.1.1.2 COMPETITION：PERFECT AND OTHERWISE We assume in this chapter that markets are perfec

13、tly competitivePerfectly competitive markets are defined by two primary characteristics：(1) the goods being offered for sale are all the same，and (2) the buyers and sellers are so numerous that no single buyer or seller can influence the market priceBecause buyers and sellers in perfectly competitiv

14、e markets must accept the price the market determines,they are said to be price takers There are some markets in which the assumption of perfect competition applies perfectlyIn the wheat market，for example，there are thousands of farmers who sell wheat and millions of consumers who use wheat and whea

15、t productsBecause no single buyer or seller can influence the price of wheat，each takes the price as given Not all goods and services，however，are sold in perfectly competitive marketsSome markets have only one seller，and this seller sets the priceSuch a seller is called a monopolyYour local cable te

16、levision company，for instance，may be a monopolyResidents of your town probably have only one cable company fromwhich to buy this service Some markets fall between the extremes of perfect competition and monopolyOne such market，called an oligopoly，has a few sellers that do not always compete aggressi

17、velyAirline routes are an exampleIf a route between two cities is serviced by only two or three carriers，the carriers may avoid rigorous competition to keep prices highAnother type of market is monopolistically competitive； it contains many sellers，each offering a slightly different productBecause t

18、he products are not exactly the same，each seller has some ability to set the price for its own productAn example is the software industryMany word processing programs compete with one another for users，but every program is different from every other and has its own price Despite the diversity of mar

19、ket types we find in the world，we begin by studying perfect competitionPerfectly competitive markets are the easiest to analyzeMoreover，because some degree of competition is present in most markets，many of the lessons that we learn by studying supply and demand under perfect competition apply in mor

20、e complicated markets as wellA.1.2 DEMAND We begin our study of markets by examining the behavior of buyersHere we consider what determines the quantity demanded of any good，which is the amount of the good that buyers are willing and able to purchaseTo focus our thinking，let's keep in mind a par

21、ticular goodice creamA.1.2.1 WHAT DETERMINES THE QUANTITY AN INDIVIDUAL DEMANDS Consider your own demand for ice creamHow do you decide how much ice cream to buy each month，and what factors affect your decision? Here are some of the answers you might give Price：If the price of ice cream rose to $20

22、per scoop，you would buy less ice creamYou might buy frozen yogurt insteadIf the price of ice cream fell to $020 per scoop，you would buy moreBecause the quantity demanded falls as the price rises and rises as the price falls，we say that the quantity demanded is negatively related to the priceThis rel

23、ationship between price and quantity demanded is true for most goods in the economy and，in fact，is so pervasive that economists call it the law of demand：Other things equal，when the price of a good rises，the quantity demanded of the good falls Income：What would happen to your demand for ice cream if

24、 you lost your job one summer? Most likely，it would fallA lower income means that you have less to spend in total，so you would have to spend less on someand probably most goodsIf the demand for a good falls when income falls，the good is called a normal good Not all goods are normal goodsIf the deman

25、d for a good rises when income falls，the good is called an inferior goodAn example of an inferior good might be bus ridesAs your income falls，you are less likely to buy a car or take a cab，and more likely to ride the bus Prices of Related Goods Suppose：that the price of frozen yogurt fallsThe law of

26、 demand says that you will buy more frozen yogurtAt the same time，you will probably buy less ice creamBecause ice cream and frozen yogurt are both cold，sweet，creamy desserts，they satisfy similar desiresWhen a fall in the price of one good reduces the demand for another good，the two goods are called

27、substitutesSubstitutes are often pairs of goods that are used in place of each other，such as hot dogs and hamburgers，sweaters and sweatshirts，and movie ticketsand video rentals Now suppose that the price of hot fudge fallsAccording to the law of demand，you will buy more hot fudgeYet，in this case，you

28、 will buy more ice cream as well，because ice cream and hot fudge are often used togetherWhen a fall in the price of one good raises the demand for another good，the two goods are called complementsComplements are often pairs of goods that are used together，such as gasoline and automobiles，computers a

29、nd software，and skis and ski lift tickets Tastes： The most obvious determinant of your demand is your tastesIf you like ice cream，you buy more of itEconomists normally do not try to explain people's tastes because tastes are based on historical and psychological forces that are beyond the realm

30、of economicsEconomists do，however，examine what happens when tastes change Expectations： Your expectations about the future may affect your demand for a good or service todayFor example，if you expect to earn a higher income next month，you may be more willing to spend some of your current savings buyi

31、ng ice creamAs another example，if you expect the price of ice cream to fall tomorrow，you may be less willing to buy an ice-cream cone at today's priceA.1.2.2 THE DEMAND SCHEDULE AND THE DEMAND CURVE We have seen that many variables determine the quantity of ice cream a person demandsImagine that

32、 we hold all these variables constant except onethe priceLet's consider how the price affects the quantity of ice cream demandedTable A1 shows how many ice-cream cones Catherine buys each month at different prices of ice creamIf ice cream is free，Catherine eats 12 conesAt $050 per cone，Catherine

33、 buys 10 conesAs the price rises further，she buys fewer and fewer conesWhen the price reaches $300，Catherine doesn't buy any ice cream at allTableA1 is a demand schedule，a table that shows the relationship between the price of a good and the quantity demandedTABLEA1 CATHERINE'S DEMAND P

34、RICEOF ICE-CREAM CONE QUANTITY OF CONES DEMANDED0120510181562425230附录BB.1 供给与需求的市场力量当寒流袭击佛罗里达时，全国超市的桔子汁价格都上升了。每年夏天当新英格兰地区天气变暖时，加勒比地区饭店房间的价格呈直线下降。当中东爆发战争时，美国的汽油价格上升，而二手凯迪拉克轿车价格下降。这些事件的共同之处是什么呢？它们都表现出供给与需求的作用。供给与需求是经济学家最常用的两个词而且有充分的理由。供给与需求是使市场经济运行的力量。它们决定了每种物品的产量以及出售的价格。如果你想知道，任何一种事件或政策将如何影响经济，你

35、就应该先考虑它将如何影响供给和需求。本章介绍供给与需求理论。它考虑买者与卖者的行为，以及他们相互之间的影响。本章要说明市场经济中供给与需求如何决定价格，以及价格又如何配置经济的稀缺资源。B.1.1市场与竞争供给与需求这两个术语是指人们在市场上相互交易时的行为。市场是某种物品或劳务的一群买者与卖者。买者作为一个群体决定了一种物品的需求，而卖者作为一个群体决定了一种物品的供给。在讨论买者与卖者的行为之前，我们首先要更充分地思考我们所说的“市场”是指什么，以及我们在经济中所观察到的不同的市场类型。B.1.1.1竞争市场市场采取了多种形式。有时市场组织健全，例如，许多农产品市场。在这些市场上，买者与卖

36、者在特定的地点与时间相聚，市场上还有拍卖者帮助确定价格并安排销售。更经常的情况是，市场并没有什么组织。例如，考虑一下某个镇上的冰激凌市场。冰激凌的买者并没有在任何一个时间相聚在一起。冰激凌的卖者在不同地方并提供略有差别的产品。这种市场上没有报出冰激凌价 在每个店买多少冰激凌。尽管这个市场没有人组织，但冰激凌买者集团和冰激凌卖者集团形成一个市场。每个买者都知道有一些卖者可供选择，而且每个卖者都认识到，他的产品与其他卖者提供的产品是相似的。冰激凌的价格和销售量并不是由任何一个买者或卖者决定的。确切地说，冰激凌的价格和销售量是由所有买者和卖者在市场上的相互交易所决定的。冰激凌市场也和经济中大多数市场

37、一样是高度竞争的。竞争市场是有许多买者与卖者，以至于每一个人对市场价格的影响都微乎其微的市场。每一个冰激凌卖者对价格的控制是有限的，因为其他卖者也提供类似的产品；卖者没有什么原因收取低于现行价格的价格，而且，如果他收取较高价格的话，买者就将到其他地方购买。同样，没有一个冰激凌买者能影响冰激凌的价格，因为每个买者购买量都很少。在本章中我们要研究竞争市场上买者与卖者如何相互影响。我们要说明，供给与需求的力量如何决定一种物品的销售量及其价格。B.1.1.2竞争：完全及其他在本章中我们假设，市场是完全竞争的。可以根据两个基本特征来定义完全竞争市场：（1）所提供销售的物品是完全相同的，以及（2）买者和卖

38、者如此之多，以至于没有一个买者或卖者可以影响市场价格。由于完全竞争市场上的买者与卖者必须接受市场决定的价格，所以，他们被称为价格接受者。有一些市场完全适用于完全竞争的假设。例如，在小麦市场上，有成千上万出售小麦的农民和千百万使用小麦和小麦产品的消费者。由于没有一个买者或卖者能影响小麦价格，所以，每个人都把价格作为既定的。但是，许多物品与劳务的市场并不是完全竞争的。一些市场只有一个卖者，而且这个卖者决定价格。这个卖者被称为垄断。例如，你们本地的有线电视公司可能就是一种垄断。你们镇上的居民也许只能从这一家有线电视公司购买有线电视服务。一些市场只有几个卖者，而且这些卖者并不总是主动地进行竞争。这种市

39、场被称为寡头。例如，一些航线就是寡头市场。如果两个城市之间的航线只由两家或二家公司提供服务，那么，这些公司就倾向于努力避免激烈竞争，以维持高价格。一些市场有许多提供略有差别产品的卖者。由于产品并不是完全相同的，每个买者都有某种决定自己产品价格的能力。这种市场被称为垄断。一个例子是软件行业。许多文字处理程序都在相互争夺使用者，但每一种程序都与其他每一种程序不同，并且有自己的价格。尽管我们在世界上看到的市场类型是多种多样的，但我们从研究完全竞争开始。完全竞争市场是最容易分析的。而且，由于大多数市场上都有某种程度的竞争，所以，我们从研究完全竞争下供给与需求中所得到的 许多结论也适用于更复杂的市场。B.1.2需求我们对市场的研究从考察买者的行为开始。在这里我们考虑什么因素决定任何一种物品的需