A Decomposition of Fertility Rates in HIV-Infected and Uninfected Women in Rural Tanzania

Kristin Bietsch, Princeton University
Mark Urassa, National Institute for Medical Research, Tanzania
Milly Marston, London School of Hygiene and Tropical Medicine (LSHTM)
Raphae Isingo, National Institute for Medical Research, Tanzania
Yusufu Kumogola, National Institute for Medical Research, Tanzania
Baltazar Mntenga, National Institute for Medical Research, Tanzania
Julius Mngara, National Institute for Medical Research, Tanzania
John Changalucha, National Institute for Medical Research, Tanzania
Benjamin D. Clark, London School of Hygiene and Tropical Medicine (LSHTM)
Basia Zaba, London School of Hygiene and Tropical Medicine (LSHTM)

This paper decomposes the fertility rates of HIV-positive and negative women from a rural population in northwestern Tanzania into the endowments and coefficients of several proximate determinants of fertility in order to better understand the fertility reduction in HIV-positive women. 11% of the differing fertility rates between HIV-positive and negative women can be explained by differences in observable characteristics. The remaining 89% is explained by differences in coefficients (or returns) by each group of women with the same characteristic. The major explanatory variables include age, marital status, coital frequency, and symptoms of other sexually transmitted infections. The large effect of coefficients in the decomposition suggests a reduced fecundability in HIV-positive women and their partners which is not easily observable.