Black applicants for Fairfax County teaching positions in a recent school year were far less likely than white candidates to get job offers even though they had on average more advanced degrees and classroom experience, according to a new study that is drawing intense scrutiny within the school system.

George Mason University researchers, who conducted the study published in the spring issue of Harvard Educational Review, did not identify the school system they were writing about. But current and former officials in Fairfax County Public Schools confirmed that the subject of the study is the 188,000-student district, largest in the Washington region and known nationally as an academic powerhouse. Fairfax was identified after the article was published and the findings triggered concern about the system’s hiring practices.

The study asserts that racial bias in hiring may be contributing to the persistent dearth of black teachers in public education, a problem that has long been pinned on a lack of qualified applicants and interest. The imbalance can have tangible effects in the classroom. Other researchers have found that black students from low-income families are more likely to graduate if they have at least one black teacher and that black teachers are more likely to identify gifted students of color.

GMU researchers examining 2012 job-application data for the school system found that black applicants had slightly lower pass rates on a screening test but somewhat more extensive academic credentials and work experience than their white counterparts. On paper, the researchers said, the black and white candidates seemed to have comparable qualifications.

Nevertheless, the study found what researchers believe is evidence of discrimination: While black candidates made up 13 percent of the applicant pool, they received 6 percent of job offers that year. Whites accounted for 70 percent of applications and received 77 percent of job offers.

“Discrimination is a powerful word and one that is often avoided because of what it connotes,” authors Diana D’Amico, Robert J. Pawlewicz, Penelope M. Earley and Adam P. McGeehan wrote in the article. “In this district, black applicants, though having many attributes similar to their white counterparts, encountered a significantly lower likelihood of being offered a job, replicating discriminatory employment patterns documented across a range of industries.” The data pointed to “discrimination in the teacher labor market,” they wrote — a problem that one of the authors said in an interview likely extends to numerous school systems.

The researchers also found that when black applicants did get job offers, they were more likely to end up in schools with large populations of minority students and high levels of poverty. They said it was evidence of “workforce segregation.”

The study did not examine how candidates did in job interviews or other face-to-face situations crucial to the hiring process.

[The nation’s teacher force lacks diversity, and it might not get much better]

Fairfax County Public Schools said in a statement that it has improved its hiring practices since 2012 and raised the number of minority teachers in its workforce, from 16 percent in 2012 to 18 percent four years later. More than 28 percent of teachers hired this school year are minorities, officials said, but they did not say what share are black.

“FCPS was not provided an opportunity to review this study and we cannot confirm the validity of the conclusions of this study based upon data from five years ago,” the statement emailed from schools spokesman John Torre said. “As a general matter, over the past several years, FCPS has made measurable and significant improvements in its hiring.”

The district said the share of black administrators and teachers “is in-line with our black student population.”

About 10 percent of Fairfax students are black, officials said, while about 7 percent of teachers and 16 percent of school-based administrators are black. The district declined to provide data on how many teachers in 2012 were black.

School system officials declined requests for interviews with school administrators and teachers about the study’s findings and their hiring practices. Interim superintendent Steve Lockard did not respond Thursday morning to a request for comment. Karen Garza, who was superintendent from 2013 to 2016, did not respond to messages seeking comment.

Jack D. Dale, superintendent from 2004 to 2013, said in a phone interview Wednesday that he was unaware of the study or its findings. While he was superintendent, Dale said, “our goal was to try and figure out how to hire the best people in our applicant pool, and that was the standard operating procedure at that time.”

One African American teacher at Mount Vernon High School, in southern Fairfax County, said the study was disheartening.

“It’s just disturbing. It’s 2017. We should have moved past this,” said the woman, who spoke on the condition of anonymity because she did not have permission to speak to the media. “It shouldn’t come down to race. If they have a higher degree and more experience, that’s what translates in the classroom, not skin color.”

Mount Vernon High serves a large number of low-income families. The teacher said it is unfair — and unwise — to steer black applicants disproportionately to high-poverty schools because of the challenges inherent in working at those schools, such as lower levels of parental involvement.

“You definitely have to have the heart for it, because it’s easy to burn out,” she said. “You deal with a lot of things that other schools don’t have to deal with.”

[Study: Black students from poor families are more likely to graduate from high school if they have at least one black teacher]

On Monday, an advisory group in Fairfax called the Minority Student Achievement Oversight Committee sent a letter to the school board about the bias claims in the GMU study. The letter urged the board to hire an “independent outside counsel to fully investigate the findings regarding alleged discriminatory hiring practices by FCPS contained in the study conducted by George Mason University professors and published in the Spring 2017 Harvard Educational Review.”

The committee is appointed by the board to offer advice on steps to improve test scores and graduation rates for minority students.

The committee letter and GMU study results come as the school board is in the midst of a high-stakes superintendent search following the resignation of Garza in September.

Fairfax County Public Schools is hardly the only high-performing system to face diversity challenges. In the Montgomery County schools of suburban Maryland, about 12 percent of teachers and 21 percent of students are black. Nationally, the share of school-age children who are black is more than 15 percent, the study said, citing census data, while 8 percent of teachers are black.

[Minority teachers in U.S. more than doubled over 25 years — but still fewer than 20 percent of educators, study shows]

Schools have worked harder in recent years to recruit more minority educators, but officials often say they are unable to find enough qualified applicants. The GMU study suggests that school systems — even those with robust recruiting efforts — could be contributing to the problem.

The researchers also looked at data on Hispanic and Asian teacher applicants and found no evidence that they were subject to hiring discrimination. The situation with black applicants, researchers wrote, was “starkly different.”

D’Amico, an assistant professor of education, said the signs of hiring bias the authors found are not unique to the school system they analyzed.

“It’s happening in this district that we study, but it’s probably happening in loads of other places,” D’Amico said. “This district is evocative but not exceptional.”

The study examined hiring and demographic data, but there was no information to assess how candidates came across in person when meeting with principals.

Eric Hanushek, a senior fellow at the Hoover Institution at Stanford University who studies teacher effectiveness, said the study offered “suggestive but not conclusive evidence” of racially based hiring. He said that researchers could not judge how a candidate performed in an interview or during a session of practice teaching. He said that research has not found that advanced degrees or even prior experience necessarily signal that a teacher will be more effective.

“We can’t easily just look at what’s on the employment application and decide whether it’s discriminatory,” Hanushek said. But he said the subject warrants further investigation.

“I think that we have to be concerned about racial discrimination in our public schools because we have a 50-year history of trying to recover from racial segregation,” Hanushek said. “I think this sounds a real warning, and I think that the school district and maybe other school districts should in fact pursue more investigation of this.”

Fairfax County Public Schools is the largest school system in Virginia and among the largest in the country. It has nearly 15,700 teachers.

The GMU study found that white principals tended to hire fewer black teachers than black principals did. The school district’s 157 white principals — 83 percent of the district total — hired 1,227 new teachers for the 2012-2013 school year. Only 49 of them were black. Meanwhile, the 24 black principals in the district hired 194 teachers, 23 of whom were black.

The authors explored possible reasons for the hiring discrepancies but concluded that discriminatory hiring practices offered the only plausible explanation. They did not name the subject of the study at the request of the district. GMU, Virginia’s largest public university, has its main campus in Fairfax County.

The researchers wrote that demand for black teachers in the district is high and that the administration went to great lengths to enlarge the pool of black candidates. Recruiters traveled widely to job fairs and visited historically black colleges and universities to advertise positions, the authors wrote.

They found that black applicants were more likely to have advanced degrees, such as a master’s, than white applicants and had, on average, almost two more years of school teaching experience outside the district. The black applicants had a slightly lower pass rate on a screening test: 58 percent reached at least a minimum score, compared with 65 percent of white applicants.

Kevin Hickerson, president of the Fairfax Education Association, which represents county schoolteachers, said part of the recruiting problem may stem from a “very decentralized” hiring process. Candidates apply through the school system, but principals and their assistants must evaluate them at each school.

“It’s really up to the school who determines who gets hired and who doesn’t,” Hickerson said. “I’m sure that there’s some bias that could creep in.”

George Becerra, father of a Fairfax first-grader and a member of the Minority Student Achievement Oversight Committee, said he was stunned by the study’s conclusions.

“It disheartens me as a parent and more importantly as a human being that this institutional practice of discrimination and bias is occurring here,” Becerra said. “It’s time to have open conversations about what is occurring.”

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