"This essay reviews the theoretical and empirical literature on quality disclosure and certification. After comparing quality disclosure with other quality assurance mechanisms and describing a brief history of quality disclosure, we address three key theoretical issues: (i) Why don't sellers...

Exploiting a natural experiment for New York City restaurants we analyze whether consumers’ quality perception is influenced by newly appearing expert opinion. As the leading restaurant guide Zagat has rated New York City’s restaurants since 1979 by drawing on consumer surveys. In 2005, with...