The roles of finance opinion and income source in the link between financial literacy and student financial behaviour in Tanzania

It is widely recognised that youth financial literacy and responsible financial behaviour are critical for inclusive economic development, closely aligned with the United Nations Sustainable Development Goals, particularly SDG 4.4. This study examined the influence of financial literacy on the financial behaviour of university students, focusing on the mediating role of Personal Finance Opinion (PFO) and the moderating role of income source (earned vs. unearned). Drawing on human capital, behavioural economics, and financial socialisation theories, this study employed a cross-sectional design and collected self-reported data from 460 students via a structured questionnaire. Hayes’ PROCESS Macro (Models 7 and 58) was used to test for moderated mediation. The results revealed that FL significantly predicted FB (β = 0.2678, p < .0.001), and PFO also positively contributed (β = 0.1445, p < 0.001). Mediation analysis showed that PFO partially transmitted the effect of FL on FB, although the explained variance was modest (2.8–7.0%). Moderation tests indicated that income strengthened both pathways: the FL → PFO link was stronger among students with earned income (interaction β = 0.0854, p = 0.001), and the PFO → FB link was also stronger (interaction β = 0.0771, p = 0.047). The indirect effect of FL through PFO on FB was significant only for students with earned income, and the robustness checks confirmed that this result remained stable and reliable. These findings demonstrate that cognitive knowledge, psychological factors, and income dynamics jointly shape financial behaviour. Although the indirect effects were modest, the study highlights the need for financial literacy interventions that build confidence and create opportunities for earned income, thereby contributing to SDGs 4, 8, and 10.