Beyond the Census: A Proxy-Based Comparative Framework to Derive a Credible Population Estimate for Nigeria Using Benchmark Economies (Ghana, Côte d’Ivoire, and Benin) with External Validation from Kenya and Tanzania

Reliable population statistics remain contentious in Nigeria, yet they are essential for planning and fiscal decision-making. This study develops and validates a multi-proxy, benchmark-calibrated framework that estimates Nigeria’s population annually using publicly verifiable indicators, including night-time lights, primary school enrolment, electricity customers, mobile subscribers, urban built-up area, and vital-events coverage, supplemented by structural controls for urbanisation, poverty, migration, and fertility–mortality dynamics. A two-way fixed-effects panel for Ghana, Côte d’Ivoire, Benin, and Nigeria (2000–2024; N = 100) provides externally derived elasticities, while six independent proxy-specific estimators generate Nigeria’s population from first principles. Temporal validation using a 2000–2014 training window and 2015–2024 testing window yields MAPE values below 2.2%, confirming predictive stability without data leakage. The 2024 calibrated median estimate for Nigeria is 223.7 million, lying within ± 3% of UN and World Bank figures. Additional external validation using Kenya and Tanzania shows deviations below ± 1.1%, demonstrating geographic robustness beyond West Africa. Diagnostic checks indicate low multicollinearity, homoskedastic residuals, and no detectable serial correlation. Overall, the framework provides an auditable, low-cost, and politically neutral supplement to censuses in data-constrained settings.