Журнал биометрии и биостатистики

Geo-Additive Modelling of Family Size in Nigeria

Abstract

Oyeronke Alaba O and Olaomi JO

We used the 2013 Nigeria Demographic Health Survey (NDHS) data to investigate the determinants of family size in Nigeria using the geo-additive model. The model was used to simultaneously measure the fixed, nonlinear, spatial and random effects. The fixed effect of categorical covariates were modeled using the diffuse prior, P-spline with secondorder random walk for the nonlinear effect of continuous variable, spatial effects followed Markov random field priors while the exchangeable normal priors were used for the random effects of the community and household. The negative binomial distribution was used to handle over dispersion of the dependent variable. Inference was fully Bayesian approach. Results showed a declining effect of secondary and higher education of mother, Yoruba tribe, Christianity, family planning, mother giving birth by caesarean section and having a partner who has secondary education on family size. Family size is positively associated with age at first birth, number of daughters in a household, being gainfully employed, married and living with partner, community and household effects.