Sovereign Wealth Management, Intergenerational Equity, and Petroleum Tax Revenue in Nigeria

This doctoral study develops an intergenerational equity framework for evaluating the management of petroleum tax revenues through Nigeria's Sovereign Wealth Fund, with particular attention to the distribution of resource wealth between current and future generations. Intergenerational equity in resource taxation requires that the depletion of non-renewable petroleum assets is offset by the accumulation of financial or productive assets that provide equivalent income streams for future generations, consistent with the Hartwick Rule and its extensions. Nigeria's Sovereign Wealth Fund, established in 2011 with three sub-funds targeting future generations, infrastructure development, and fiscal stabilisation, provides the institutional structure but has been characterised by inadequate capitalisation and recurring fiscal pressure-driven withdrawals. The study develops a modified Hartwick Rule framework calibrated to Nigeria's petroleum depletion path, incorporating an endogenous governance quality parameter that discounts the productive value of public investment under poor institutional conditions. Empirical analysis uses a dynamic programming approach to derive the optimal savings and investment allocation rule for petroleum tax revenues across the three SWF mandates, tested against historical fund behaviour. Sustainability gap accounting quantifies the annual deviation of actual petroleum revenue savings from the intertemporally optimal path. The study expects to find that Nigeria has systematically undersaved petroleum revenues by an amount representing several percent of annual GDP, creating a structural intergenerational equity deficit. Original contributions include the governance-adjusted modified Hartwick Rule model. Keywords: sovereign wealth fund, intergenerational equity, petroleum tax revenue, Hartwick Rule, fiscal sustainability.