Mike Luca on Yelp

My colleague Mike Luca (whose work I wrote about here when he was still a grad student) has a paper on the influence of Yelp reviews on restaurant revenues.

It's recently been receiving some attention both locally at HBS working knowledge, and in the larger blogosphere: One-Star Bump On Yelp Leads To Big Revenue Boost, Study Finds

Here's the abstract of his paper:
"Do online consumer reviews affect restaurant demand?  I investigate this question using a novel dataset combining reviews from the website Yelp.com and restaurant data from the Washington State  Department of Revenue.   Because  Yelp prominently displays a restaurant's rounded average rating,  I can  identify the  causal  impact of Yelp ratings on demand with a  regression discontinuity framework that exploits Yelp‟s rounding thresholds.  I present three findings about the impact of consumer reviews on the restaurant industry: (1) a one-star increase in Yelp rating leads to a  5-9 percent increase in revenue, (2) this effect is driven by independent restaurants; ratings do not affect restaurants with chain affiliation, and (3) chain restaurants have declined in market share as Yelp penetration has increased. This suggests that  online  consumer reviews substitute for more traditional forms of reputation. I then test whether  consumers use these reviews  in a way that is consistent with standard  learning models.  I present  two additional findings: (4) consumers do not use all available information and are more responsive to quality changes that are more visible and (5) consumers respond more strongly when a rating contains more information.  Consumer response to a restaurant‟s average rating is affected by the number of reviews and whether the reviewers are certified as “elite” by Yelp, but is  unaffected by the size of the reviewers‟ Yelp friends network." "