Cornelia Pechmann University of California-Irvine

David W. Stewart University of Southern California

In 1971, the Federal Trade Commission (FTC) began sanctioning--and even
encouraging--the use of comparative advertising. Since then, this type of ad-
vertising has become quite prevalent, and numerous studies have been done
to determine how effective it is. The objective of this chapter is to present a
comprehensive review of the more than 30 comparative advertising studies that
have been published to date. This review is designed to enhance our under-
standing of the psychological processes that underlie consumer responses to
comparative advertising. It also highlights the managerial implications of how
consumers respond to comparative advertising by delineating under what con-
ditions comparative advertising has been found to be most effective and in terms
of what measures of effectiveness.

This review focuses on the relative effectiveness of comparative ads that are
in compliance with government regulations. The FTC requires that compara-
tive ads be substantiated by objective empirical data demonstrating that the
advertised brands are noticeably superior to the comparison brands on the fea-
tured dimensions, and that these dimensions are important to consumers ( Ginter
& Starling, 1977). Therefore, comparative ads must contain unique selling
propositions (USP) or brand differentiating messages. Hence, the specific is-
sue that this review seeks to address is when and why advertisers should use
comparative ads rather than noncomparative ads to communicate their brands'
unique selling propositions.

Advertisers can use either direct or indirect comparative ads (as well as non-
comparative ads) to communicate their brands' unique selling propositions.

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