ch6 需求.ppt

Chapter Six,Demand需求,Properties of Demand Functions,Comparative statics analysis（比较静态分析）of ordinary demand functions-the study of how ordinary demands x1*(p1,p2,y)and x2*(p1,p2,y)change as prices p1,p2 and income y change.,Structure,Own-price changesPrice offer curve（价格提供曲线）Ordinary demand curveInverse demand curve（反需求函数）Income changesIncome offer curve（收入提供曲线）Engel curve（恩格尔曲线）Cross-price effects,Own-Price Changes,How does x1*(p1,p2,y)change as p1 changes,holding p2 and y constant?Suppose only p1 increases,from p1 to p1 and then to p1.,x1,x2,p1=p1,Fixed p2 and y.,p1x1+p2x2=y,Own-Price Changes,Own-Price Changes,x1,x2,p1=p1,p1=p1,Fixed p2 and y.,p1x1+p2x2=y,Own-Price Changes,x1,x2,p1=p1,p1=p1,Fixed p2 and y.,p1=p1,p1x1+p2x2=y,x1*(p1),Own-Price Changes,p1=p1,Fixed p2 and y.,x1*(p1),p1,x1*(p1),p1,x1*,Own-Price Changes,Fixed p2 and y.,p1=p1,x1*(p1),x1*(p1),p1,x1*(p1),p1,p1=p1,x1*,Own-Price Changes,Fixed p2 and y.,x1*(p1),x1*(p1),p1,x1*(p1),x1*(p1),p1,p1,x1*,Own-Price Changes,Fixed p2 and y.,x1*(p1),x1*(p1),x1*(p1),p1,x1*(p1),x1*(p1),p1,p1,p1=p1,x1*,Own-Price Changes,Fixed p2 and y.,x1*(p1),x1*(p1),x1*(p1),p1,x1*(p1),x1*(p1),x1*(p1),p1,p1,p1,x1*,Own-Price Changes,Ordinarydemand curvefor commodity 1,Fixed p2 and y.,x1*(p1),x1*(p1),x1*(p1),p1,x1*(p1),x1*(p1),x1*(p1),p1,p1,p1,x1*,Own-Price Changes,Ordinarydemand curvefor commodity 1,p1 price offer curve,Fixed p2 and y.,Own-Price Changes,The curve containing all the utility-maximizing bundles traced out as p1 changes,with p2 and y constant,is the p1-price offer curve.The plot of the x1-coordinate of the p1-price offer curve against p1 is the ordinary demand curve for commodity 1.,Own-Price Changes,What does a p1 price-offer curve look like for Cobb-Douglas preferences?,Then the ordinary demand functions for commodities 1 and 2 are,Take,Own-Price Changes,and,Notice that x2*does not vary with p1 so thep1 price offer curve is flat and the ordinarydemand curve for commodity 1 is a rectangular hyperbola.,