A leading academic has presented a paper which claims Google prioritizes its own services over competitors when performing local searches. If the European Union was looking for more ammunition to fuel its antitrust case against Google, this would certainly be it.

Columbia Law School processor Tim Wu, responsible for coining the term "net neutrality," co-authored the paper alongside Michael Luca of the Harvard Business School and the data team at Yelp. It was presented at Oxford University' Antitrust Enforcement Symposium this past weekend.

As Bloomberg notes, Google has long since maintained that it creates better experiences for its users by supplying its own answers to queries at the top of search results. In many cases, like asking the answer to a math calculation or when converting currency, Google's answers are indeed helpful to end-users according to Wu.

It's when asking specific subjective questions, like what's the best pediatrician in San Francisco, that trouble arises.

The data team at Yelp conducted a series of blind A/B testing on Internet users in which half were shown Google's typical results while the others received modified results that showed the most relevant external listings according to Google's algorithm.

Yelp concludes that users were 45 percent more likely to pick the modified merit-based search results. Whether or not more clicks equates to better search results, however, is up in the air and will likely play a role in Google's defense.