Towards a Socioecological Model of Igbo Language Shift in Urban Nigeria: Evidence from Longitudinal Data in Three Cities

This dissertation develops and tests an original socioecological model of Igbo language shift using longitudinal survey data collected over a ten-year period from Igbo-speaking communities in Lagos, Abuja, and Kano, providing the first longitudinal quantitative account of urban Igbo language shift dynamics in Nigeria. Most existing language shift research in Nigeria relies on cross-sectional data that conflates cohort effects with period effects, making dynamic modelling of the shift process impossible. The study follows three hundred and twelve Igbo families recruited in 2014 across the three cities, administering comparable language use, attitude, and proficiency assessments at five-year intervals in 2019 and 2024. Multilevel growth curve modelling is applied to the longitudinal data, controlling for family composition changes, geographic mobility, and socio-economic trajectory. The socioecological model integrates individual-level language attitude variables, household-level language practice variables, and community-level ecological variables including co-ethnic density, institutional Igbo presence, and inter-ethnic marriage rates into a predictive model of language maintenance and shift. Findings confirm accelerating shift trajectories in all three cities over the decade, with Kano showing the fastest shift rate and Lagos the most complex, non-linear trajectory. The model identifies community-level Igbo institutional presence as the variable most amenable to policy intervention. An evidence-based urban Igbo language maintenance policy package is proposed as the dissertation's applied output. Keywords: Igbo language shift, socioecological model, longitudinal study, urban Nigeria, language maintenance.