Measuring and Testing Advertising-Induced Rotation in the Demand Curve

(A7)

(A8)

(A9)

∂ lnη_i^RM
∂ ln A_i

^{d ln}(^-cii )   ^{d ln} wi

∂ ln A_i    ∂ ln A_i

n

∑w α -α and
j ij ii

j

∂ηAD^s = - c_ii∂w_i
∂ ln A_i w2∂ ln A_i

ⁱⁱ (∑ w α - α ).
j ij ii

j

Dividing (A8) by η_i^AIDS yields:

∂ lnηⁱ_AIDS
∂ ln A_i

nn

(^-cii ! w )(∑ w a ^- α ) (cii / wi )(∑ w a ^- a )
i=j

^- ( cii / wi^- 1)                  ( cii / wi^- 1)

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