Toward a Jurisprudence of Islamic Economic Justice: Theory, Doctrine and Application to Nigerian Wealth Inequality

Islamic economic jurisprudence contains extensive doctrinal resources for addressing wealth inequality through obligations of Zakat, Sadaqah, Waqf, and the prohibition of riba and hoarding, yet these resources have not been systematically theorised as a coherent jurisprudence of economic justice applicable to contemporary Nigerian wealth distribution challenges. This study develops an original jurisprudence of Islamic economic justice and applies it analytically to the structural challenges of wealth inequality in Nigeria. A theoretical and applied doctrinal methodology is applied. The theoretical phase constructs the jurisprudence through systematic integration of Maqasid al-Shariah theory on wealth protection and distribution, classical Fiqh al-Muamalat provisions on economic obligations, and contemporary Islamic economic justice scholarship from Choudhury, Chapra, and Asutay. The applied phase analyses the distribution mechanisms, legal obligations, and institutional frameworks governing Zakat, Waqf, and riba prohibition across Nigeria's Islamic finance and Sharia state contexts, evaluating their aggregate contribution to wealth redistribution against the Gini coefficient evidence on Nigerian wealth inequality from CBN and NBS reports from 2018 to 2023. The original theoretical contribution is a Doctrine of Islamic Distributive Jurisprudence for Nigeria, specifying a three-tier framework of mandatory redistribution (Zakat, Nafaqa), voluntary redistribution (Sadaqah, Waqf), and structural prohibition (riba, ihtikar/hoarding) with institutional design proposals for each tier. Available Islamic economic justice theory identifies the gap between Islam's redistributive doctrine and institutional performance as the central theoretical problem. Keywords: Islamic economic justice, Zakat, wealth inequality, Nigeria, distributive jurisprudence.