Seniority-based hiring policies in San Diego Unified mean the poorest schools usually end up with the least experienced teachers. Black and Latino students who attend poor schools are disproportionately suspended and expelled.

And one paragraph buried deep within a 63-page report from the school district shows that the two issues could be directly compounding each other.

For decades, San Diego Unified has wrestled with the fact that black and Latino students are over-represented in discipline rates. As part of an effort to monitor progress on that issue, the district recently released a study comparing suspension rates from 2011-2012 to previous years.

Though the report acknowledges the disparities are likely the result of many factors, it highlights one dynamic that has played out again and again at San Diego Unified.

Referencing research from The Journal of Negro Education, the report says:

“More likely, as the author suggested, it is better explained by an interaction of multiple factors, in which African American students tend to live in low-income neighborhoods, and schools in these neighborhoods tend to have a difficult time retaining experienced teachers. Inexperienced teachers may have a harder time responding to discipline issues effectively and serving students’ needs academically.”

This indicates less-experienced teachers, who are more likely to be found at poorer schools, might suspend students because they lack veteran teachers’ classroom management skills.

That idea validates the fundamental point made by California students in Vergara v. California, who argued that the weakest teachers disproportionately end up in low-income schools. A judge agreed, though the case is certain to be appealed.

The convoluted system San Diego uses to staff schools may compound the problem. Based on an agreement with the teachers union, so-called post-and-bid policies mean that when teachers leave or retire, principals can only pick a replacement from a pool of the five most senior candidates.

In the past, the district has waived that requirement for certain high-poverty schools. The thinking was schools in low-income areas already have difficulties attracting experienced teachers, so the waiver would make it easier for them to hire those who want to be there.

And the fact that the district is now saying that teacher inexperience likely has something to do with the high suspension rates puts folks like trustee Richard Barrera – who argued seniority policies should be preserved – in an awkward situation. (For the record, Barrera told me it’s layoffs that disproportionately hurt poorer schools, not seniority policies).

But what does a teacher’s experience have to do with suspending kids?

First of all, it’s important to note that the largest share of suspensions are doled out in the classroom. So it makes sense to begin here.

Vernon Moore, San Diego Unified’s executive director of student services, reiterated that the reasons for the racial disparities are complex, and can’t be pinned down to any one factor.

That said, he told me that looking at the correlation between suspension rates and teachers’ experience is worthy of further exploration.

Setting behavioral expectations for students, and being consistent enough to establish classroom norms, is something that takes teachers time to develop, he said.

Moore, a former teacher and a principal at a school for students who have been expelled, said teachers who have never been in a struggling school may be more likely to suspend students instead of trying to have a conversation about what caused the behavior.

But nor does Moore want to teacher-blame.

“Look, I don’t want to lay this all on the feet of new teachers. I’ve had some new teachers who are extremely culturally proficient and can build a rapport with students very quickly,” he said.

And that’s why the biggest piece of the district’s plan to improve the problem is to train teachers and principals, on an on-going basis, to recognize their own biases and perceptions.

The challenge is persuading teachers and principals that suspensions are overused, while helping them find alternative ways to deal with behavioral problems.