State spending on TK–12 education has increased over the past decade, but teacher staffing remains a key issue. At a recent virtual briefing, PPIC researchers Iwunze Ugo, Brett Guinan, and Julien Lafortune discussed a new report that focuses on recent spending in relation to a range of teacher staffing metrics.

Recovery from the Great Recession, the passage of Proposition 30 (2012)—temporary tax increases partly directed to education—and a pandemic-era funding infusion boosted education spending from about $12,000 per pupil in the 2012–13 school year to more than $21,000 per pupil in 2023–24.

Research shows that teachers have a big impact on student outcomes, and the state has invested in policies and programs designed to add well-trained teachers to the workforce and build skills among teachers already working in California schools. How much of this increased funding has gone to teacher salaries, and how has it affected metrics such as student-teacher ratios, as well as teacher training and experience?

Ugo noted that these metrics can provide a concrete sense of teacher quality. “Research has found meaningful gains for students whose teachers have more experience, training, and education,” he added. For example, “the impact a teacher can have on student performance grows significantly in the first three to five years on the job.”

Spending on teachers has increased across all school districts, but additional dollars have also been allocated to other spending areas. What about districts with large shares of high-need students (low-income, English Learner, and foster youth)—which get extra state funding from the Local Control Funding Formula (LCFF)? Have these districts spent more on teacher staffing?

“We found that even though higher-need districts were spending a lot more on teachers and instructional staff, they weren’t necessarily spending more than other districts that got less of the targeted spending,” said Julien Lafortune.

“We saw high-need districts spending more on other areas, such as instructional materials, additional staff—such as teacher’s aides and support staff,” said Ugo. “That points to the breadth of the challenges facing these districts.”

How has increased spending affected metrics such as student-teacher ratios and teacher qualifications? Class sizes have been falling since the recession—from about 25 to roughly 21 students per teacher—due to a combination of declining enrollment and new teacher hires. Almost all (95%) teachers are fully credentialed, and the shares of fully credentialed teachers have been relatively high for some time.

The report also looks at “clear assignments,” or the alignment of a teacher’s credentials and the subject area(s) they are assigned to teach. Research suggests that teachers who are certified to teach in a given subject have a greater positive impact on student outcomes, particularly in science and math.

This makes it especially notable that many schools face challenges in these two subject areas. While more than half of students attend a school where 83% to 86% of teachers are in a clear assignment in every subject, Brett Guinan noted that “10% of students attend a school where less than half of math teachers are in clear assignments and only about 40% of teachers are clearly assigned in science.” Moreover, the schools with the biggest challenges in these areas serve large shares of high-need students.

The overall takeaway is that teacher metrics have been improving, and disparities in teacher metrics across student groups are small. “We’ve made a lot of progress—especially since the recession—on student-teacher ratios, as well as clear assignments and credentialing,” said Lafortune. “But looking at hard-to-staff schools really does suggest that additional strategies are needed.”

Guinan concurred: “We saw the most notable differences when we compared schools with the largest and smallest teacher staffing challenges,” she said. “I think that really gets at the importance of targeting interventions. Supporting specific schools might be more effective than broad statewide solutions.”