Statistical Analysis of Ethnic Diversity and Economic Productivity in Nigerian Metropolitan Cities

Ethnic diversity in Nigerian cities is often studied through a sociological lens, but its statistical relationship with economic productivity provides quantitative evidence relevant to urban economic policy and social cohesion investment decisions in metropolitan contexts. This study statistically analyses the relationship between ethnic diversity and economic productivity in Nigeria's five largest metropolitan cities: Lagos, Kano, Ibadan, Port Harcourt, and Benin City. Cross-sectional LGA-level data from the 2023 NBS urban survey and Afrobarometer Module 8 provided ethnic fractionalisation indices and economic productivity proxies including GDP per capita estimate, formal employment rate, and enterprise density. Pearson and Spearman correlations and multivariate regression examined diversity-productivity associations controlling for city governance quality, infrastructure access, and educational attainment. Ethnic fractionalisation indices ranged from 0.62 in Kano (low diversity) to 0.88 in Lagos (high diversity). Regression analysis showed a positive association between ethnic diversity and enterprise density (beta = 0.39, p = 0.007) and a non-linear inverted-U relationship with formal employment rate, peaking at moderate diversity levels. High diversity LGAs showed higher innovation proxy scores. Governance quality moderated the diversity-productivity relationship significantly. The study contributes quantitative evidence to the Nigerian diversity-development debate and recommends inter-ethnic economic integration programmes and equitable service delivery as complementary policies to harness urban diversity dividends in Nigerian metropolitan governance. Keywords: ethnic diversity, economic productivity, metropolitan cities, regression analysis, Nigeria