07生产技术与利润最大化(09-10-30)(1).ppt

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,*,*,*,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,*,7.,生产技术与利润最大化,7.1,技术（,Technologies,）,7.1.1,什么叫技术？,技术是投入转换为产出的过程,E.g.labor,a computer,a projector,electricity,and software are being combined to produce this lecture.,Usually several technologies will produce the same product.,a blackboard and chalk can be used instead of a computer and a projector.,Which technology is“best”?,How do we compare technologies?,2,7.1.2 Production Functions,y denotes the output level.,The technologys,production function,states the,maximum,amount of output possible from an input bundle.,3,Production Functions-One input,one output,y=f(x),x,1,Input Level,x,Output Level,y,1,y,1,=f(x,1,)is the maximal output level obtainable from x,1,input units.,4,Technologies with Multiple Inputs,Suppose the production function is,(x,1,x,2,)=(1,8),(x,1,x,2,)=(8,8),5,Technologies with Multiple Inputs,Output,y,x,1,x,2,(8,1),(8,8),6,Isoquants with Two Variable Inputs,y,8,y,4,x,1,x,2,7,用产量面表示生产函数,L,O,K,TP,K,1,L,1,L,2,K,2,A,A,B,B,C,C,D,D,Q,1,Q,2,E,1,F,1,G,1,E,2,F,2,G,2,E,1,E,2,G,1,G,2,8,Isoquants with Two Variable Inputs,Output,y,x,1,x,2,y,8,y,4,9,Cobb-Douglas Technologies,A Cobb-Douglas production function is of the form,10,Fixed-Proportions Technologies,A fixed-proportions production function is of the form,11,Fixed-Proportions Technologies,x,2,x,1,minx,1,2x,2,=14,4,8,14,2,4,7,minx,1,2x,2,=8,minx,1,2x,2,=4,x,1,=2x,2,12,Perfect-Substitutes Technologies,A perfect-substitutes production function is of the form,13,Perfect-Substitution Technologies,9,3,18,6,24,8,x,1,x,2,x,1,+3x,2,=9,x,1,+3x,2,=18,x,1,+3x,2,=24,14,有限种投入比的技术,1,2,3,4,5,6,7,8,1,2,3,4,5,6,7,8,R,1,X,2,:X,1,=8:1,R,2,X,2,:X,1,=3:1,R,3,X,2,:X,1,=1:1,R,4,X,2,:X,1,=1:4,现有,6,单位,x,1,和,3,单位,x,2,2,单位,x,1,和,2,单位,x,2,用于,R,3,，生产产品,50,单位；,4,单位,x,1,和,1,单位,x,2,用于,R,4,，生产产品,50,单位,产量,100,单位的等产量线,15,7.1.3 Marginal(Physical)Products,The marginal product of input i is the rate-of-change of the output level as the level of input i changes,holding all other input levels fixed.,That is,16,Marginal(Physical)Products,17,7.1.4 Returns-to-Scale,Marginal products,describe the change in output level as a,single,input level changes.,Returns-to-scale,describes how the output level changes as,all,input levels change in,direct proportion,(,e.g.,all input levels doubled,or halved).,18,Constant returns-to-scale,If,for any input bundle(x,1,x,n,),then the technology described by theproduction function f exhibits,constantreturns-to-scale,.,E.g,.(k=2)doubling all input levelsdoubles the output level.,19,Constant returns-to-scale,y=f(x),x,x,Input Level,Output Level,y,2x,2y,Constantreturns-to-scale,20,Diminishing returns-to-scale,If,for any input bundle(x,1,x,n,),then the technology exhibits,diminishing returns-to-scale,.,E.g,.(k=2)doubling all input levels less than doubles the output level.,21,Diminishing returns-to-scale,y=f(x),x,x,Input Level,Output Level,f(x),2x,f(2x),2f(x),Decreasingreturns-to-scale,22,Increasing returns-to-scale,If,for any input bundle(x,1,x,n,),then the technology exhibits,increasingreturns-to-scale,.,E.g,.(k=2)doubling all input levelsmore than doubles the output level.,23,Increasing returns-to-scale,y=f(x),x,x,Input Level,Output Level,f(x),2x,f(2x),2f(x),Increasingreturns-to-scale,24,Returns-to-Scale,y=f(x),x,Input Level,Output Level,Decreasingreturns-to-scale,Increasingreturns-to-scale,25,Examples of Returns-to-Scale,The perfect-substitutes productionfunction is,The perfect-substitutes productionfunction exhibits,constant returns-to-scale,.,26,Examples of Returns-to-Scale,The perfect-complements productionfunction is,The perfect-complements productionfunction exhibits,constant returns-to-scale,.,27,Examples of Returns-to-Scale,The Cobb-Douglas production function is,28,Examples of Returns-to-Scale,The Cobb-Douglas technologys returns-to-scale is,constant,if,a,1,+a,n,=1,increasing if a,1,+a,n,1,decreasing,if,a,1,+a,n,1,29,Question and answer,Q:,在边际产出递减的情况下，是否能存在规模报酬递增现象？,A:Yes.,E.g.,30,Returns-to-Scale,diminishes as x,1,increases,diminishes as x,1,increases,所以，即使边际产出是递减的，规模报酬也可能是递增的。,31,7.1.5 Technical Rate-of-Substitution,At what rate can a firm substitute one input for another without changing its output level?,32,Technical Rate-of-Substitution,x,2,x,1,y,100,The slope of an isoquant is its,technical rate-of-substitution,.,33,技术替代率的计算,0,34,7.1.6,长期和短期,The long-run,is,the,circumstance in which a firm is,unrestricted,in its choice of,all input levels,.,There are many possible short-runs.,A short-run,is,a,circumstance in which a firm is,restricted,in some way in its choice of,at least one input level,.,35,长期和短期,is the long-run productionfunction(both x,1,and x,2,are variable).,The short-run production function whenx,2,1 is,The short-run production function when x,2,10 is,36,x,1,y,长期和短期,Four short-run production functions.,37,7.2,Profit-Maximization,7.2.1 Economic Profit,厂商用投入,j=1,m,生产产品,i=1,n.,产出水平,y,1,y,n,，投入水平,x,1,x,m,.,产品价格,p,1,p,n,，投入价格,w,1,w,m.,厂商是价格接受者，即,p,1,p,n,和,w,1,w,m,给定。,经济利润：,38,经济利润,投入量、产出量及利润均为流量；,经济成本,39,7.2.2,企业现值,某厂商若干时期的经济利润为,0,1,2,利率为,r,，厂商经济利润的现值为,40,7.2.3,不变要素和可变要素,数量固定的生产要素称为不变要素（固定要素）。,可以按不同的数量使用的生产要素称为可变要素（变动要素）。,长期、短期与不变要素、可变要素,41,7.2.4,短期利润最大化,假定要素,2,的投入水平 保持不变，厂商的利润最大化问题就可以表示为,销售收入,变动成本,固定成本,42,利润最大化,生产要素的边际产品价值,(the marginal revenue product of input 1),应该等于它的价格,x,1,￥,pMP,1,w,1,x*,1,43,几何法,等利润线,(Iso-Profit Lines),slope,vertical intercept,44,Iso-Profit Lines,Increasing profit,y,x,1,45,Short-Run Profit-Maximization,x,1,y,46,Short-Run Profit-Maximization;A Cobb-Douglas Example,47,7.2.5,比较静态学,产品价格,p,变动,x,1,y,低价格,高价格,48,比较静态学,投入价格,w,1,变动,x,1,y,高价格,低价格,49,Comparative Statics of Short-Run Profit-Maximization,An increase in p,the price of the firms output,causes,an increase in the firms output level(the firms supply curve slopes upward),and,an increase in the level of the firms variable input(the firms demand curve for its variable input shifts outward).,50,Comparative Statics of Short-Run Profit-Maximization,An increase in w,1,the price of the firms variable input,causes,a decrease in the firms output level(the firms supply curve shifts inward),and,a decrease in the level of the firms variable input(the firms demand curve for its variable input slopes downward).,51,7.2.6,长期利润最大化,所有要素的使用量都可以自由的变动,要素需求曲线,52,7.2.7,反要素需求曲线,x,1,￥,w,1,x,1,pMP,1,w”,1,x”,1,w,1,53,1,、字体安装与设置,如果您对PPT模板中的字体风格不满意，可进行批量替换，一次性更改各页面字体。,在,“,开始”,选,项卡,中,，点击“,替,换”按,钮右,侧箭,头,，,选,择“,替,换,字,体,”。（如下,图）,在图“替换”下拉列表中选择要更改字体。（如下图）,在“替换为”下拉列表中选择替换字体。,点击“替换”按钮，完成。,54,2,、替换模板中的图片,模板中的图片展示页面，您可以根据需要替换这些图片，下面介绍两种替换方法。,方法一：更改图片,选中模版中的图,片,（,有些图片与其他,对象,进行了组合，,选,择,时,一定要选中图,片 本身，而不是组合）。,单击鼠标右键，选择“更改图片”，选择要替换的图片。（如下图）,注意：,为防止替换图片发生变形，请使用与原图长宽比例相同的图片。,54,赠送精美图标,