EFFECT OF POPULATION STRUCTURE ON ECONOMIC GROWTH IN NIGERIA

Abstract

This study examined the effect of population structure on economic growth in Nigeria using annual time-series data spanning from 1981–2025. The study employed descriptive statistics, Augmented Dickey–Fuller (ADF) and Phillips–Perron (PP) unit root tests, the Autoregressive Distributed Lag (ARDL) bounds testing approach, Error Correction Model (ECM), and Pairwise Granger causality test to analyse both the long-run and short-run relationships among the variables. The ARDL bounds test established the existence of a long-run equilibrium relationship between population structure and economic growth. In the long run, the old-age dependency ratio exerted a positive and weakly significant effect on economic growth, whereas the coefficients of the male and female working-age population were statistically insignificant. The short-run dynamics revealed significant asymmetric effects of the working-age population, with the female working-age population exhibiting an initial negative but subsequently positive impact on economic growth, while the male working-age population demonstrated the opposite pattern. The error correction term was negative and statistically significant, indicating that approximately 35.8% of short-run disequilibrium is corrected annually. Furthermore, the Pairwise Granger causality results showed no causal relationship between population growth rate, male population growth, female population growth, and economic growth. The study recommends policies aimed at enhancing labour productivity, expanding productive employment, promoting female economic participation, strengthening human capital development, and integrating demographic planning into national development strategies to fully harness Nigeria's demographic dividend.