Caregiving to older people with needs has been mainly dependent on informal care provision by female caregivers. Compared with the care burden gender gap, the within-gender gap in women's socioeconomic status (SES) has attracted less policy attention. We investigated the association between middle-aged women's SES and the likelihood of being a primary caregiver for elderly informal care, focusing on household income, women's marital status, work status, and educational background under the universal and public system of formal long-term care provision in Japan.
