PITTSBURGH—A large-scale field experiment conducted by Carnegie Mellon University researchers has found evidence that sharing personal information via online social networks can lead to hiring discrimination.

Alessandro Acquisti, associate professor of information technology and public policy at CMU's H. John Heinz III College, and Christina Fong, senior research scientist at CMU's Dietrich College of Humanities and Social Sciences, tested the impact that information posted on a popular social networking site by job candidates can have on employers' hiring behavior. Their manuscript is available on the Social Science Research Network at http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2031979.

"Our experiment focused on a novel tension: the tension between the law — which, in the United States, protects various types of information, making it risky for certain personal questions to be asked during interviews — and new information technologies, such as online social networks — which make that same information often available to strangers, including interviewers and employers," Acquisti said.

Alessandro Acquisti, associate professor of information technology and public policy at CMU's H. John Heinz III College.Photo courtesy of Carnegie Mellon UniversityWhile various surveys have suggested that employers have been using the Web to screen prospective job candidates, there have been no controlled experiments measuring the frequency of firms' usage of online profiles in hiring decisions and how profile information actually affects those decisions.

Based on their research, Acquisti and Fong estimated that a minority of U.S. employers regularly searches for candidates online.

"While it appears that a relatively small portion of U.S. employers regularly searches for candidates online, we found robust evidence of discrimination among certain types of employers," Fong said.

Acquisti and Fong used data revealed online by actual members of popular social networking and job-seeking sites to design job candidate resumes and online profiles for their experiments. They experimentally manipulated personal traits the candidates revealed online regarding religion and sexual orientation, while holding signs of professionalism and work ethic constant.

The researchers first used a survey experiment involving more than 1,000 online participants to capture reactions to the candidates' resumes and online profiles, and to test whether or not the candidates' profiles appeared realistic.

Then, in the field experiment, Acquisti and Fong submitted applications on behalf of the candidates to real job openings at more than 4,000 U.S. employers. They collected data that helped them get a sense of how many employers searched for job candidates online. The researchers measured the number of interview opportunities a Christian candidate received relative to a Muslim candidate, and the number of interview opportunities a gay candidate received relative to a straight candidate. They also collected data on the states and counties in which jobs were located and on the firms that listed the openings.

Christina Fong, senior research scientist at CMU's Dietrich College of Humanities and Social Sciences.Photo courtesy of Carnegie Mellon University"Our survey and field experiments show statistically significant evidence of hiring bias originating from information candidates shared on their online profiles," Fong said. "Both by itself and controlling for a host of demographic and firm variables, our Muslim candidate was less likely to receive an interview invitation compared to our Christian candidate in more politically conservative states and counties."

The researchers point out that, because the political leaning of states and counties in the field experiment cannot be randomly assigned, the results should be interpreted as correlational, not causal.

In both the survey and field experiments, Acquisti and Fong detected less bias based on the sexual orientation of the candidates. Interview rates for the gay candidates were similar to those for the straight candidates.

The findings suggest that, while hiring discrimination via Internet searches and social media does not seem widespread, the impact of revealing certain traits online can have a significant effect on the behavior of employers who look online for candidates' personal information.

"Employers' use of online social networking sites to research job candidates raises a variety of notable implications, since a vast number of job candidates reveal personal information on these sites that U.S. employers can't ask in an interview or infer from a resume," Acquisti said.