A hurdle negative binomial regression model for non-marital fertility in Namibia

Pazvakawambwa, Lillian; Indongo, Nelago; Kazembe, Lawrence N.

A hurdle negative binomial regression model for non-marital fertility in Namibia

Date

2014

Authors

Pazvakawambwa, Lillian

Indongo, Nelago

Kazembe, Lawrence N.

Abstract

The rise of non-marital fertility, which seems to defy the Bongaarts model by decoupling marriage from fertility, has become a subject of interest in both the developed and developing world. Consequences of non-marital fertility are mostly negative particularly in developing countries. In Namibia, although premarital childbearing has been reported to be high and increasing, no studies have explicitly analyzed factors influencing non-marital fertility. This paper uses data from the 2006/7 Namibia DHS to establish the determinants of non-marital fertility among women by applying a two-part model, with one part to describe the presence of non-marital birth and the other part to explain its intensity (number of children born). Using the number of children ever born as an outcome, we explored various count data models. Based on the Voung statistics model comparison, we settled for the Hurdle logit Negative Binomial regression to model the number of non-marital births. Non-marital fertility in Namibia is associated with the age, with young women likely to have lower fertility compared to older women. Women with secondary or higher education had lower fertility compared those with no formal education. Findings also show that rural women higher fertility propensity compared to their urban counterparts even though there was no significant difference in fertility intensity. With regard to socio-economic status, fertility intensity decreased as the women got richer. Intervention efforts should focus on promoting education among girls and women especially in rural areas to improve their socio-economic status, reduce teenage pregnancy and non-marital fertility.

Keywords

Two-part models, Non-marital fertility, Namibia

Citation

Pazvakawambwa, L., Indongo, N., & Kazembe, L. (2014). A hurdle negative binomial regression model for non-marital fertility in Namibia. Journal of Mathematics and System Science, 4, 498-508.