Quantity Index Numbers pP If Lg= xi+p2×2<1 en p1x1+p2X2 pixi+p2x2<p1x1+p2x2 so consumers overall were better off in the base period than they are now n the current period 北京大学经济学院 Slide36
北京大学经济学院 Slide36 Quantity Index Numbers • If then so consumers overall were better off in the base period than they are now in the current period. L p x p x p x p x q b t b t b b b b = + + < 1 1 2 2 1 1 2 2 1 p x p x p x p x b t b t b b b b 1 1 + < 2 2 1 1 + 2 2
Quantity Index Numbers If Pg= xi+p2×2 pix tpixo-7 en piXi+p2X2>p1X1+p2x2 so consumers overall are better off n the current period than in the base erlo 北京大学经济学院 Slide37
北京大学经济学院 Slide37 Quantity Index Numbers • If then so consumers overall are better off in the current period than in the base period. P p x p x p x p x q t t t t t b t b = + + > 1 1 2 2 1 1 2 2 1 p x p x p x p x t t t t t b t b 1 1 + > 2 2 1 1 + 2 2
Price index(价格指数) A price index is a quantity-weighted average of price p ,tpx px,+px, 1, 2 can be base perio d quantities (X1, *2 )or current period quantities (×1x2) 北京大学经济学院 Slide38
北京大学经济学院 Slide38 Price Index（价格指数） • A price index is a quantity-weighted average of price; • (x1,x2) can be base period quantities (x1b,x2b) or current period quantities (x1t,x2t). 1 2 1 2 1 2 1 2 p x p x p x p x I b b t t q ++ =
Price Index Numbers If(x1x2)=(×1b×2) then we have the Laspeyres price index(拉氏价格指数 L=P1x1 +p2x2 1R+nrb 6 b 北京大学经济学院 Slide 39
北京大学经济学院 Slide39 Price Index Numbers • If (x1,x2) = (x1b,x2b) then we have the Laspeyres price index(拉氏价格指数); b b b b t b t b p p x p x p x p x L 1 1 2 2 1 1 2 2 + + =
Price Index Numbers If (x1,X2)=(x, 2t), then we have the paasche price index(帕氏价格指 数) pixit p2x2 pI p2x 北京大学经济学院 Slide40
北京大学经济学院 Slide40 Price Index Numbers • If (x1,x2) = (x1t,x2t) ，then we have the Paasche price index（帕氏价格指 数）; b t b t t t t t p p x p x p x p x P 1 1 2 2 1 1 2 2 + + =