Filtered reviews are a terrible proxy for fake reviews!
Yelp is widely believed (among business owners) to wield review filtering/deletion as a club to "encourage" small businesses to buy advertising on yelp.com.
The economic incentives behind review fraud seem pretty obvious to me.
That's why we checked whether advertisers are getting preferential filtering treatment. (They aren't according to our data.) Read my previous comment, or better yet read the paper where we also explain possible pitfalls in the analysis.
Yelp is widely believed (among business owners) to wield review filtering/deletion as a club to "encourage" small businesses to buy advertising on yelp.com.
The economic incentives behind review fraud seem pretty obvious to me.