Like many other media services, internet search services provide two-sided platforms that coordinate interactions between media consumers and media advertisers. As with other media services, especially newspapers, the possibility has been raised that positive feedback between the consumer and...

It has been argued that internet search is a two-sided process where consumer and advertiser demand form a feedback loop, an effect that has contributed to high concentration in newspapers, yellow pages and the magazine industries. This paper employs a simultaneous equations model to test for a...