"We think, by systematically raising the bar, we're asking all of our students, regardless of what school district they go to, regardless of what neighborhood they live in, to arrive with more similar levels of preparation," Minor said.
He also said that racial disparities in STEM (science, technology, engineering and math) fields can be traced directly back to high school, and the proposed requirement would help lessen those.
Cal State data show that students who enter their first year of college having taken an additional quantitative reasoning course are more likely to complete their general education math requirement, return for their second year and graduate. The data do not show a causal link, but Minor said the correlations are strong enough, across ethnic and income groups and over time, to guide policy making.
Overall, research shows that academic preparation in high school, including in math, is the strongest predictor of college success, said Michal Kurlaender, a professor of education at the University of California, Davis who researches educational pathways and access to college.
But it can be difficult to parse out how much of that success is a result of purely academic achievement, or of a host of other factors that enabled students' preparation, such as a better school or home environment or stronger teachers.
Kurlaender said there is some evidence that when higher standards are put in place, schools can and do rise to the occasion. She said, however, there can also be unintended consequences in a statewide K-12 system, in which there are deep disparities in college readiness.
"The implications of a policy like this will not be evenly felt," Kurlaender said. "They will be disproportionately targeting students who are less likely to be found in this pathway already."
Those are Latinx students, black students, low-income students and students who attend schools where seniors don't currently take math, according to a paper Kurlaender and her colleagues published last week.
Critics of the proposal argue that such findings are precisely the reason to reject such a requirement or, at least, slow down before adopting it.
Arrillaga, of Education Trust-West, pointed to state data showing that 8 out of 10 black and Latinx students in California do not meet math standards.