《曼昆经济学原理Chap04.ppt

供给和需求的市场力量The Market Forces of Supply and Demand Chapter 4 第四章 供给和需求的市场力量The Market Forces of Supply and Demand 供给 和需求是经济学家使用最频繁的两个词汇。 Supply and demand are the two words that economists use most often. 供给 和 需求是市场经济运行的力量。Supply and demand are the forces that make market economies work. 现代微观经济学研究的就是供给、需求和市场均衡。Modern microeconomics is about supply, demand, and market equilibrium. 市场Markets 市场 是某种物品和劳务的一群买者和卖者。 A market is a group of buyers and sellers of a particular good or service. 供给和需求指的是当人们在市场上买卖（相互作用）时的行为。 The terms supply and demand refer to the behavior of people . . . as they interact with one another in markets. 市场Markets 买方决定需求Buyers determine demand. 市场类型：竞争市场Market Type: A Competitive Market 竞争市场是 ：A competitive market is a market. . . 完全竞争与其它市场Competition:Perfect and Otherwise 产品是同质的 Products are the same 有许多买者和卖者，个人不能影响价格Numerous buyers and sellers so that each has no influence over price 买卖双方都是价格接受者 Buyers and Sellers are price takers 完全竞争与其它市场Competition:Perfect and Otherwise 垄断Monopoly 一个卖者，买方控制价格 One seller, and seller controls price 寡头Oligopoly 很少几个卖者 Few sellers 并不总是激烈竞争 Not always aggressive competition 完全竞争与其它市场Competition:Perfect and Otherwise 需求 Demand 需求量 是买方愿意并且能够购买的某种商品的数量Quantity demanded is the amount of a good that buyers are willing and able to purchase. 需求的决定 Determinants of Demand 市场价格 Market price 消费者收入 Consumer income 相关物品的价格 Prices of related goods 嗜好（偏好）Tastes（preference) 预期 Expectations 上课要象我一样专注，吭！ 需求法则 Law of Demand 需求法则 描述的是商品价格和需求量之间的反向关系。其它条件相同时，价格上升，需求量下降。 The law of demand states that there is an inverse relationship between price and quantity demanded. 需求表 Demand Schedule 需求表 是表示 物品价格和需求量之间关系的表格 The demand schedule is a table that shows the relationship between the price of the good and the quantity demanded. 需求表 Demand Schedule 需求曲线 Demand Curve 需求曲线是把价格和需求量 联系起来的一条向下倾斜的曲线。 The demand curve is the downward-sloping line relating price to quantity de