New research indicates that racial discrimination is factor in the nation’s shortage of black teachers.

A Harvard Educational Review study looked at hiring patterns in a large public school district. In 2012, black and white teachers who applied for jobs in the unidentified district were equally qualified, the researchers found. But white teachers received a disproportionate number of job offers.

Only six percent of black job applicants received offers, whereas 77 percent of white applicants received offers. Black teachers were more likely to receive job offers from schools with black principals. And black teachers were more likely to by hired by schools with high rates of low-income and minority students.

The district hired Hispanic and Asian-American applicants at rates proportional to the number of applicants. The imbalance was unique to black teachers.

The study author and researcher, Diana D’Amico, said the school district was shocked by the results of the study. The district prided itself on its efforts to recruit minority applicants. Administrators had attributed the lack of black teachers to a paucity of black applicants.

The Huffington Post reported on the results of this study on April 12, 2017.