Evidence continues to mount that when it comes to search results, Google isn't always playing fair.

The latest accusation comes from a new study written by Harvard Business School professor Michael Luca, Columbia Law School Professor Tim Wu, and Yelp's data science team. In it, the researchers claim that Google is skewing its local search results in favor of Google-created content. That suggestion shouldn't come as a surprise to anyone who's been paying attention. In recent years, Google's search rankings were the subject of a Federal Trade Commission investigation, as well as an ongoing antitrust investigation by European Union regulators.

Though the FTC ended the investigation in 2013 without bringing legal charges against Google, The Wall Street Journal recently uncovered an internal FTC report arguing that Google was, in fact, abusing its power in search and that it was causing "real harm to consumers and to innovation in the online search and advertising markets.”

At the time, Yelp's vice president of public policy, Luther Lowe, told the Journal, “This document appears to show that the FTC had direct evidence from Google of intentional search bias."

Faced with inaction by the FTC, however, it seems Yelp decided to make the case against Google itself by commissioning a study. In it, the researchers created two separate versions of local search results. The first version showed results that included Google's so-called Local OneBox, which shows a select list of businesses at the top of the search page generated from Google+. Google's argument for OneBox is that it shows searchers exactly what they're looking for at the top of the page, without them needing to scroll through 10 blue links. That means, among other things, that OneBox results show up above Yelp results, but appear objective to the end user. Google argues, that the immediacy of OneBox improves search. But the researchers tested this theory by creating a second version of the same search results—only this time without OneBox. This version surfaced results that were generated using Google's organic search algorithm.

The team then randomly displayed one of the two sets of results to 2,690 subjects. What they found was that users were 45-percent more likely to actually click through the search results on the second version, which included only organic results. What that means, they write, is that by prizing OneBox over organic links Google is serving up less useful search results, which is therefore damaging to the end user.

"From this paper one thing should be abundantly clear," the authors write. "The easy and widely disseminated argument that Google's universal search always serves users and merchants is demonstrably false. Instead, in the largest category of search (local intent-based), Google appears to be strategically deploying universal search in a way that degrades the product so as to slow and exclude challengers to its dominant search paradigm."

The paper goes on to emphasize the many ways that these skewed search results harm consumers, which is key to any antitrust case, and which the FTC seemed unable to adequately prove during its investigation two years ago. The paper argues that when users don't get the best search results, they experience harm because they either give up on the search, take more time to find the result they're looking for, or end up patronizing a subpar business. "The harm caused by such misdirection when it occurs, will vary, but is undeniable in the aggregate," the paper reads.

The problem with all this is that, generally, even though they are the ones being harmed, consumers don't care all that much—at least not enough to change their habits. The only ones who can truly force Google to change are the regulators themselves. The FTC passed on that opportunity. But after years of deliberating, the European Commission, which has recently been cracking down on American tech companies, may finally have a chance.