CPP also has about half local commuter students, while CPSLO has very few (presumably since there are not that many people who live within commuting distance of CPSLO).
However, for lower income families, CSU financial aid policy strongly encourages attending a local CSU, since there is no adjustment for living on/near campus versus commuting from home, unlike at UC. For many lower income families, the cost comparison can end up CSU commuter < UC < CSU resident. Since nearly all CPSLO students have to live on/near campus, CPSLO often ends up being disadvantageous in costs compared to UCs and commuter CSUs for lower income families. CPSLO is by far the lowest in Pell grant percentage among frosh (13.2%) and all undergraduates (20.1%) among all California public universities.