ln r
jt
¼z
jt
β + γ ln a
jt
+ α ln q
jt
+ ν
jt
,
where r
jt
is advertising price, a
jt
is quantity of advertising, and ν
jt
is an unobservable.
Rysman’s instrument for usage, q
jt
, of directory j is the number of households who have
recently moved to market t. The instrument for advertising quantity includes cost shifters,
such as the local wage. The demographic shifters z
jt
include population coverage of the
directory. (Note that this variable is naturally excluded from Ryman’s nested logit model
of usage share.)
Fan (2013) follows Rysman in modeling advertiser demand (in column inches) as a
function of ad rate (in dollars), r
jt
, audience size (circulation), q
jt
, market number of
households, H
jt
, and an unobservable ν
jt
,
ln a
jt
¼λ
0
+ λ
1
ln H
jt
+ λ
2
ln q
jt
+