va
1
, a
2
, α, β, xðÞ¼u
0
ωα +1ωðÞ1 βðÞxðÞ
2
γωa
1
γ 1 ωðÞa
2
;
where γ represents the nuisance parameter of advertising.
Gal-Or and Dukes (2003) use this framework to analyze content choice in media
markets. They find that platforms choose the same location on the Hotelling line, a result
in stark contrast to the one obtained in the traditional framework. In the model of
Gal-Or
and Dukes (2003)
, consumers obtain content for free but incur a disutility from adver-
tising. Advertisers compete in the product market and inform consumers about their
products via advertising. A lower advertising intensity leads to less-intense product mar-
ket competition, implying that advertisers’ prices and profits are higher. Each platform
and advertiser negotiate about the payment made by the advertiser in return for adver-
tising on the platform. In this negotiation, the two parties maximize their joint surplus
and share it equally. By choosing minimal differentiation, platforms reduce the amount of
advertising in equilibrium because advertising is a nuisance to consumers. Hence, intense
competition for consumers in the media market results in low advertising levels. Via min-
imal differentiation platforms commit to a low advertising intensity, thereby reducing
product market competition. This, in turn, allows advertisers to reap higher profits. Since
platforms do not set advertising prices but negotiate with producers, minimal differen-
tiation does not lead to zero advertising prices but increases the surplus in the
negotiation.
27
Gabszewicz et al. (2004) also consider multi-homing consumers but do not consider
advertiser competition in the product market. Instead, they assume that the disutility of
consumers is convex in the advertising level—that is, the disutility from advertising is a
i
θ
,
with θ 1. As they show, in equilibrium, platforms may choose a location in the interior
range of the Hotelling line; that is, the content is relatively similar.
28
In fact, the equi-
librium locations are closer to each other, the larger is θ. That is, the program diversity
is smaller, the larger is the advertising aversion of consumers (measured by increasing
marginal disutility of advertising).
These papers are based on the idea that consumers mix the time that they spend on
different platforms, keeping the total amount of time fixed. However, in most markets,
the availability of content increases consumption. These features have been incorporated
27
Exclusive advertising contracts are a different means to mitigate competition between advertisers. These
contracts are standard practice, e.g., in the US television industry. By offering single-category advertising
rights, a platform guarantees not to sell another slot in the same advertising break to any close competitor.
Therefore, consumers are less informed about competing products, yielding higher profits for advertising
firms. For a detailed analysis, see
Dukes and Gal-Or (2003).
28
Peitz and Valletti (2008) also find that platforms do not choose “maximal” differentiation to obtain higher
surplus from advertisers in case consumers obtain content for free. Their model is cast in a framework in
which all consumers single-home and advertisers multi-home. However, as they note, their results carry
over to a setting in which consumers mix content.
474
Handbook of Media Economics