New York, Apr 5 (IANS): Facebook's ad delivery algorithm have an inherent system that discriminates based on race and gender even when advertisers have no such plans, researchers have found.

The team from Northeastern University, the University of Southern California and non-profit organisation Upturn said their "results demonstrate previously unknown mechanisms that can lead to potentially discriminatory ad delivery, even when advertisers set their targeting parameters to be highly inclusive".

To reach this conclusion, the researchers spent over $8,500 on ads that they say reached millions of people, linking to actual job-hunting or real estate sites, among other categories.

"They ran the same campaigns with different ad copy or photos or at different price rates, checking the demographic breakdowns provided by Facebook on each campaign," reports The Verge.

"We find that both the advertiser's budget and the content of the ad each significantly contribute to the skew of Facebook's ad delivery," said the team.

"We observe significant skew in delivery along gender and racial lines for 'real' ads for employment and housing opportunities despite neutral targeting parameters," they added.

The US Department of Housing and Urban Development (HUD) in March charged Facebook with housing discrimination, saying the social media giant encouraged and caused housing discrimination through ad targeting.

"Facebook is discriminating against people based upon who they are and where they live. Using a computer to limit a person's housing choices can be just as discriminatory as slamming a door in someone's face," HUD Secretary Ben Carson said in a statement.

The department accused Facebook of allowing advertisers to exclude certain people from seeing ads, including parents, people born outside the US, non-Christians and those interested in Hispanic culture or accessibility matters.