The changing religious composition of Nigeria: causes and implications of demographic divergence

At nearly  million inhabitants, Nigeria is Africa’s most populous country by twofold and fertility levels remain higher than most other sub-Saharan African nations. Throughout the last several decades, the fertility gap between Christians and Muslims has widened with significant political implications for a nascent democracy. Where the DHS survey of  revealed a non-significant difference of · children, this figure had increased to · children by . As the total fertility rate (TFR) of Christians decreased significantly from · to · children per woman between  and , the TFR of Muslims increased from · to · children per woman. The timing of this divergence coincides with the formal institutionalization of Sharia law in . We examine the role of religion on education, contraception and family behaviour. Finally, we touch upon the implications for population growth and the religious composition of Nigeria in the coming decades. I N T R O D U C T I O N At nearly  million inhabitants, Nigeria is the most populous country in Africa by twofold and is on course to become one of the largest countries in the world. It is also one of the most diverse, with a large number of groups from different linguistic and ethnic backgrounds (Katzner ; Lieberman and McClendon ). Nigeria is also the only state in the world with equal proportions of Christians (·% in ), located mainly in the South, and Muslims (·%) (PEW ) who are living mainly in the Northern regions of the country (Figure ). The population balance between the two majority religions, however, is likely to shift in the future as a result of distinctly different trajectories of demographic change. While the Muslim North is currently in an early phase of demographic transition with very high fertility rates, fertility rates of Christians and Muslims in the South are declining as the demographic transition is further underway. These diverging trajectories in demographic behaviour may lead to the end of the current equilibrium between the two religions with significant implications for the future of the country. Within this study we examine possible explanations for divergent population trajectories along religious lines as well as the path that these trajectories may potentially take into the future. As with several other Western African countries, ethno-regional and religious divides largely overlap in Nigeria and are manifested in a pronounced north-south gap (Mancini ). Here, inequalities have emerged along geographic and ethnic divisions as well as along socioeconomic lines between nomadic herdsmen and farmers, exacerbated by climate change (e.g. Fasona & Omojola ; Sayne ). While  M A R C I N S T O N A W S K I E T A L .