Racial Differences in Social Capital Volunteer Activities: A Mixed-Methods Longitudinal Study of How Race and Place...

Volunteering is a key component of social capital associated with improved health outcomes. However, it remains unclear how volunteer patterns differ by race and education and whether standard measures adequately capture racial and contextual differences in how volunteering is understood and reported. This mixed-methods study examined racial and educational differences in volunteer activities over time and evaluated how individuals from different racial backgrounds define, engage in, and value volunteering. This study used a mixed-methods longitudinal design combining secondary analysis of the Midlife in the United States (MIDUS) study (1995-2016; n = 5921) with qualitative interviews (n = 47) in the United States. The quantitative outcome was the number of self-reported volunteer hours per month across four domains: healthcare, youth-related, political, and other organizations. Linear mixed-effects models were used to examine differences by race, volunteer context, and time, adjusting for age, gender, and educational attainment. Qualitative interviews used MIDUS item probes and open-ended questions to examine participants' interpretations of volunteer work, unpaid activities, and forms of engagement. Black participants reported significantly higher volunteer hours than White participants (β = 0.97, p = 0.007). Volunteering varied by context, with higher engagement in school and youth-related (β = 1.12, p < 0.001) and other organizational activities (β = 2.80, p < 0.001) and lower engagement in political contexts (β = -0.45, p < 0.001), relative to healthcare settings. Volunteering increased modestly over time (Wave 2: β = 0.45, p < 0.001; Wave 3: β = 0.39, p < 0.001). Interaction analyses indicated that racial differences varied across contexts, with a significantly smaller increase in volunteering within "other" organizations among Black participants relative to White participants (β = -1.29, p = 0.006). Qualitative findings indicated that Black participants more often engaged in community-based and informal activities, including work within community organizations, whereas White participants more frequently participated in formal volunteering. Urban residents reported more flexible engagement compared with suburban residents' structured participation. Volunteering is shaped by structural and contextual factors. Public health research and interventions should adopt more inclusive measures to better capture diverse forms of civic engagement.