October 19, 2021
How Facebook’s Advertising Algorithms Can Discriminate By Race and Ethnicity
- This study examines racial and ethnic biases in the targeting of ads on Facebook’s advertising platform in January 2020 and January 2021, before and after a major July 2020 boycott of Facebook by advertisers over issues of misinformation and civil rights.
- In 2021, Facebook’s new “African-American Culture” ad targeting option contained 75% fewer White users than the old “African American (US)” option removed the previous year.
- Facebook’s tools to help advertisers find users similar to their existing customers generated biased target lists that included either more African-Americans or more Whites, depending on which racial group was dominant in an advertiser’s submitted customer list. This was true for both the Lookalike Audience tool and the Special Ad Audience tool that Facebook designed to explicitly not use sensitive demographic attributes when finding similar users.
- The degree of bias toward African-Americans or Whites in the composition of a Lookalike or Special Ad audience was greater when customer lists of individuals with racially stereotypical names or ZIP codes were used as the basis for each tool.
- Similarly, lookalike audiences can also be biased toward Asians. An audience generated by using a customer list of Asians with stereotypical names and ZIP codes as the source list was 100% Asian. Lookalike audiences based on source lists of Hispanics also overrepresented Hispanics.