FINANCIAL MATHEMATICS AND INFORMAL MICROCREDIT: ANALYSIS OF KIXIKILA AND ZUNGU PRACTICES IN THE MUNICIPALITY OF QUIBALA AS ALTERNATIVE FINANCIAL SYSTEMS

Abstract

This article investigates kixikila and zungu practices in the municipality of Quibala, Cuanza-Sul, Angola, as alternative systems of informal microcredit and savings, analysing them through the instruments of Financial Mathematics. The central objective is to reveal, with mathematical rigour, the real cost of informal credit within these community structures, comparing it with available formal alternatives, and to assess their role as mechanisms of financial inclusion for populations excluded from the conventional banking system. Adopting a mixed methodology, questionnaires were administered to 80 active participants in kixikilas and zungu in the municipality, and semi-structured interviews were conducted with 12 organisers of these systems. Results reveal that, although the implicit interest rates in these practices frequently exceed those of formal bank credit, with effective annual rates ranging between 24% and 144% the ease of access, absence of formal collateral requirements, and community trust make these systems rationally preferable for most participants. The study demonstrates that the pedagogical application of Financial Mathematics concepts, including simple interest, compound interest, effective rate, and present value can transform these practices from tools of vulnerability into instruments of financial empowerment. Recommendations are proposed for integrating financial literacy into non-formal education programmes and microfinance models in Angola.