Google has become ubiquitous with online search. According to a research paper published Monday, the company has been abusing its position as the go-to search engine for the Web by promoting its own products in search results.

The researchers behind the study consisted of members of the Yelp data science team, Michael Luca of the Harvard Business School, and legal scholar and former Federal Trade Commission adviser Tim Wu, best known for his role in popularizing the concept of net neutrality. In a paper titled “Is Google degrading search? Consumer Harm from Universal Search,” the group concludes that Google is “reducing social welfare—leaving consumers with with lower quality results and worse matches.”

The paper reaches this conclusion after conducting experiments through a randomized, controlled trial in which Google’s self-serving results were compared to results with external content displayed. The results of the research found users were 45 percent more likely to engage with search results that were produced organically, leading to the conclusion that Google is promoting itself over better results.

Tim Wu’s involvement in the paper marks a turnaround in the opinion of Wu, who previously believed Google had successfully passed on its own merits an FTC investigation into the company’s potentially biased search service. Wu now sees Google’s treatment of search results in the same vein as Microsoft‘s bundling of Internet Explorer browser with its Windows operating system: an attempt to promote the company’s own product when better alternatives are available.

Both Wu and Lucia were paid for by Yelp for their time and involvement in the research project. Yelp, a major competitor of Google’s when it comes to local information, has participated in anti-Google campaign and encouraged European Union regulators to pursue an antitrust suit against the search giant.

H/T The Verge | Photo via jacinta lluch valero/Flickr (CC BY SA 2.0)