微观经济学课件Ch_04

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,The Market Forces of Supply and Demand,供给与需求的市场力量,Chapter 4,The Market Forces of Supply and Demand,市场的供给和需求力量,Supply,and,Demand,are the two words that economists use most often.,供给和需求是经济学家最常用的两个术语。,Supply,and,Demand,are the forces that make market economies work.,供给和需求即是推动市场经济运行的力量所在,Modern microeconomics is about supply,demand and equilibrium.,现代微观经济学研究供给、需求和均衡。,Markets,市场,A,market,is a group of buyers and sellers of a particular good or service.,市场是由某个商品或服务的买者和买者组成的群体,The terms supply and demand refer to the behavior of people as they interact with one another in,markets,.,术语供给和需求指人们的行为,当他们在市场中相互作用时。,The buyers as a group determine the,demand,.,买方作为一个整体决定需求,The sellers as a group determine the,supply,.,卖方作为一个整体决定供给,Market Type,市场类型,A,competitive market,is a market in which,竞争性市场是指这样的市场：,with many buyers and many sellers,有许多的买者和卖者,that is not controlled by any one person,市场不受任何一个人操纵,in which a narrow range of prices are established that buyers and sellers act upon.,买者和卖者所遵循的价格被约束在窄小的范围内。,Competition:Perfect and otherwise,竞争：完全竞争与否,Perfect competition:,完全竞争,Products are all the same,产品完全相同,Numerous buyers and sellers so that each has no influence over the price,有无数的卖者和买者以至与任何人不能影响价格,Buyers and sellers are price takers,买者和买者都是价格接受者,No entry barriers,没有进入壁垒,Competition:Perfect and otherwise,竞争：完全竞争与否,Monopoly:,完全垄断,One seller,seller controls price,一个卖者，买者控制价格,Oligopoly:,寡头垄断,Few sellers,少数几个卖者,Not always aggressive competition,竞争不一定总是很激烈。,Monopolistic Competition:,垄断竞争,Many sellers,许多卖者,Slightly differentiated products,产品有微小差别,Each seller may set price for its own product,每一个卖者都能为自己的产品设定价格。,Demand,需求,Quantity demanded,is the amount of a good that buyers are willing and able to purchase.,需求量是买者愿意且能够购买的量,The,Law of Demand,states that,ceteris paribus,there is an inverse relationship between price and quantity demanded(,Giffen,Goods).,需求法则是说，其他条件不变的情况下，价格和需求量负相关（吉芬商品）,Ceteris paribus is a Latin phrase that means all variables other than the ones being studied are assumed to be constant.Literally,it means other things being equal.,Ceteris Paribus,是一个拉丁习词，指除了被研究的变量外，其他变量都假定是不变的。,Demand Curve,需求曲线,$3.00,2.50,2.00,1.50,1.00,0.50,2,1,3,4,5,6,7,8,9,10,12,11,Price of Ice-Cream Cone,Quantity of Ice-Cream Cones,0,Market Demand,市场需求,Marker demand,refers to the sum of all individual demands for a particular good or service.,市场需求是所有个人对某个商品或服务的需求总和。,Graphically,individual demand curves are summed,horizontally,to obtain the market demand curve.,从图形上看，将个人需求曲线水平加总就得到了市场需求曲线。,The Market Demand Curve,市场需求曲线,Price of Ice-Cream Cone,Price of Ice-Cream Cone,Price of Ice-Cream Cone,2.00,2.00,2.00,4,3,7,1.00,1.00,1.00,8,5,13,Quantity of Ice-Cream Cones,Quantity of Ice-Cream Cones,Quantity of Ice-Cream Cones,Catherines Demand,Nicholass Demand,Market Demand,+,=,When the price is$2.00,Catherine will demand 4 ice-cream cones.,When the price is$2.00,Nicholas will demand 3 ice-cream cones.,The market demand at$2.00 will be 7 ice-cream cones.,When the price is$1.00,Catherine will demand 8 ice-cream cones.,When the price is$1.00,Nicholas will demand 5 ice-cream cones.,The market demand at$1.00,will be 13 ice-cream cones.,The market demand curve is the horizontal sum of the individual demand curves!,Determinants of Demand,需求的决定因素,Marker price,市场价格,Consumer income,消费者收入,Prices of related goods,相关商品的价格,Tastes,偏好,Expectations,预期,Population,人口,Change in Quantity Demanded vs.Change in Demand,需求量的变化和需求的变化,Change in Quantity Demanded,需求量的变化,Movement along the demand curve.,沿着需求曲线,Caused by a change in the price of the product.,由商品价格变化导致,Change in Demand,需求的变化,A shift in the demand curve,either to the left or right.,需求曲线发生移动：左移或右移,Caused by a change in a determinant other than the price.,由除了价格以外的影响需求的其他因素变化导致,Changes in Quantity Demanded,需求量的变化,0,D,1,Price of Cigarettes per Pack,Number of Cigarettes Smoked per Day,A tax that raises the price of cigarettes results in a movement along the demand curve.,A,C,20,2.00,$4.00,12,Changes in Demand,需求的变化,0,D,1,Price of Ice-Cream Cone,Quantity of Ice-Cream Cones,D,3,D,2,Increase in demand,Decrease in demand,Consumer Income,消费者收入,As income increases the demand for a,normal good,will increase.,随着收入的增加，对正常品的需求会增加,Necessaries,必需品,Luxuries,奢侈品,As income increases the demand for an,inferior good,will decrease.,随着收入的增加，对劣等品的需求会减少,Consumer,Income:Normal,Good,消费者收入,$3.00,2.50,2.00,1.50,1.00,0.50,2,1,3,4,5,6,7,8,9,10,12,11,Price of Ice-Cream Cone,Quantity of Ice-Cream Cones,0,Increase,in demand,An increase in income.,D,1,D,2,Consumer Income,:,Inferior Good,消费者收入：劣等品,$3.00,2.50,2.00,1.50,1.00,0.50,2,1,3,4,5,6,7,8,9,10,12,11,Price of Ice-Cream Cone,Quantity of Ice-Cream Cones,0,Decrease,in demand,An increase in income.,D,1,D,2,Prices of Related Goods,相关品价格,Substitutes&Complements,替代品和互补品,When a fall in the price of one good reduces the demand for another good,the two goods are called,substitutes,.,如果一个商品的价格下降会减少另外一个商品的需求，则这两种商品称为替代品。,When a fall in the price of one good increases t