Spatial Pattern and Determinants of Age at Marriage in Nigeria Using a Geo-Additive Survival Model

Age at first marriage, after controlling for socio-economic and demographic variables, varies across regions and districts. A geo-additive hazard model allows for measuring spatial effects. The nonlinear and baseline effects are modeled by Bayesian penalized splines; spatial components are treated as correlated random effects following a Markov random field. Application is based on data from 1999, 2003, and 2008 Nigeria Demographic and Health Surveys. Age at first marriage is positively associated with education and urbanization and depends on religion. It presents a north-south divide.