1、23455050505050505062502603003154007Totalcostin short run:in long run:TotalcostVariablecost=FixedcostVariablecost+8910For an airline flying planes with empty seats,the added cost of another passenger is quite low.But on a hot summer day,when everyones conditioners are running,the added electric power
2、 comes at a high marginal cost.11MC=TCq TCq-1 =(VCqFC)(VCq-1FC)=VCq VCq-112OutputTotal costOutputMarginal cost13141516Average cost(or unit cost)=total costoutput=TCq=ACAveragefixed cost=fixed costoutput=FCq=AFCAveragevariable cost=variable costoutput=VCq=AVC1718ACq+1=ACqqMCq+1q1=ACq(q1)MCq+1ACqq1=AC
3、qMCq+1ACqq119QuantityAC and MC=AVCqMCq+1AVCqq1AVCq+1AVC20Tangent lineTotal cost curve1 unit of outputMarginal costaaTCMCQ2122LaborMarginal product of laborMarginal costOutputABDABDMCACIn the short run:2324To a given output:Marginal product of input A APrice of input A A=Marginal product of input B B
4、Price of input B B=25BBAAMPPMPP1$1$This gives you the marginal product per dollar of output.2627MP of LaborPrice of Labor=MP of CapitalPrice of Capital2829303132333436Q=100 2LAQ=output;L=labor;A=land.The production function is a constant-returns-to-scale production function,a special case of the Cob
5、b-Douglas production function.37Constant returns to scaleLaborLand38Diminishing marginal product of laborLaborLand39Diminishing marginal product of landLaborLand404142LaborLand43LandLaborABCDqEqual-product curve or isoquantThere are an infinite number of equal-product contour lines(等值线等值线)in the map
6、.44LandLaborABDqCALMACLNMN:AMPA=L MPLALMPMPLA45LandLaborLabor price=$2,Land price=$3TC=$3TC=$6TC=$9TC=$12TC=$15TC=$18equal-cost Line:TCqPqPAALL46LandLaborTC=$3TC=$6TC=$9TC=$12TC=$15equal-cost Line:TCqPqPAALLALAPA=L PLALPPLA47LandLaborTC=$3TC=$6TC=$9TC=$12ABCDALMPMPLAALPPLAALALPPMPMP48ALALPPMPMPAALLPMPPMP
