The percentage of new teachers of color hired by Denver schools this year is lower than last year, when the district recruited its most diverse group of new teachers ever.

Whereas 30% of new hires last year were teachers of color, only 26% are this year, according to numbers provided by Denver Public Schools. Despite efforts to diversify Denver’s teacher workforce, it remains overwhelmingly white.

Denver Public Schools officials suspect the decrease in teacher diversity could be an unintended consequence of a new teachers contract negotiated during a three-day strike in February. The new contract raises salaries, especially for veteran teachers.

“We saw an increase in the number of experienced candidates applying for jobs across our schools,” said Katie Clymer, director of the district’s talent acquisition team. Anecdotally, she said they found that “those teachers with experience are predominantly white.”

Teacher diversity is important in Denver because 75% of students are black, Hispanic, Asian, Native American, or multiracial. But this school year, 72% of teachers are white. That number does not include teachers who work at independent charter schools.

Research shows teacher diversity matters. One study found black students from low-income families who have even one black teacher in elementary school are more likely to graduate.

School principals are not mandated to hire teachers with more experience, Clymer said, but they often do, even if the principals also value diversity. She said the district strongly encourages principals to watch candidates teach, in person or by video, before hiring them.

“If you’re watching an experienced teacher with five to 10 years of classroom management versus a teacher coming out of a teacher prep program, you’re going to see a big difference,” Clymer said. “When principals are balancing the needs of a school, often having an experienced teacher who has success with a population like ours is going to outweigh a lot of other factors.”

The district has several efforts underway to diversify its teacher workforce, including recruiting from universities that serve black and Latino college students, as well as a “pipeline” approach that helps Denver students become teachers aides, and helps teachers aides become teachers. But because those efforts are newer, they haven’t yet had a big impact, Clymer said.

Here is a breakdown of the diversity of the 634 new teachers hired this year:

470 are white (74%)

104 are Latino (16%)

30 are black (5%)

17 are multiracial (3%)

13 are Asian (2%)

Clymer noted that the percentage of new hires who are black – 5% – is higher than the percentage of black teachers in the district’s workforce as a whole, which is 4%.

Clymer also pointed what she and others suspect are positive effects of the new teacher contract. They include a decrease in the number of job postings – which could indicate an increase in teacher retention, though official numbers are not yet available – and fewer vacant positions at the start of school.