Page 11 - IJPS-11-3

International Journal of
Population Studies Role of nuptiality patterns to fertility

analysis was selected because it is a valuable approach that 2.3. Ethical considerations
identifies the primary sources of change in an outcome. The The study was conducted using secondary data from
method also divides the two elements into segments that the DHSs Program. The ICF/ORC Institutional Review
illustrate the distinct contribution of each predictor to both Board has examined and approved the procedures
components through a detailed decomposition process. and questionnaires for routine DHSs. In addition, the
Finally, a Poisson-based multivariate decomposition model Ethiopian Health and Nutrition Research Institute and
for nonlinear responses (mvdcmp in Stata version 17) was the Institutional Review Board offices of the Ministry
performed to identify factors contributing to the change of Science and Technology of Ethiopia granted ethical
in the lifetime fertility between 2000 and 2016 to identify approval to the study methods. After the respondents’
the sources of changes in the CEB among married women oral agreement, interviews were undertaken. To safeguard
aged 35 and above (Daniel and Myeong, 2009; Powers et al., respondents’ anonymity, the names of respondents and
2011). The general decomposition equation is as follows: personal identifiers were not included in the final data.

Y 2016 Y 2000  FX 2000 2000 FX 2016 2016 (I) 3. Results
Table 2 shows the distribution of women by selected
Equation I will further decompose to Equation II: demographic and socio-economic variables in Ethiopia.

Y 2016 Y 2000 FX 2000 2000 FX 2016 2000 The weighted sample constituted a total sample of 8610
FX 2016 2000 FX 2 2016 2016 (II) Table 2. CEB by the percentages of Ethiopian women aged 35
and above by selected characteristics and survey year

where Y 2016 Y− 2000 is the mean difference in CEB Variables and categories Survey years CEB
between the 2016 and 2000; F (·) is a logarithmic function 2000 2016 p 2000 2016
mapping a linear combination of X (Xβ) to Y; X represents Educational level
predictors; and β represents regression coefficients. No education 91.51 73.37 0.001 6.6 6.3
The year 2000 was the comparison group, and the Primary 5.76 18.92 0.001 5.1 5.4
year 2016 was the reference group. The compositional Secondary+ 2.73 7.72 0.001 4.1 2.5
characteristics reflect the expected difference if 2016 Place of residence
was given the year 2000’s distribution of covariates. Urban 14.88 18.64 0.001 5.1 3.7
The coefficient reflects the expected difference if 2016 Rural 85.12 81.36 0.001 6.7 6.3
experienced the year 2000’s behavioral responses to X. This Agrarian region 91.99 89.22 0.001
study is based on secondary data of women aged 35 and
above collected in the 2000 and 2016 DHSs. The women Tigray 6.65 7.63 0.077 6.3 5.7
aged 35 years and above in both the 2000 and 2016 surveys Amhara 28.19 25.58 0.006 6.3 5.7
were asked about their birth histories, and this provided Oromiya 34.84 35.06 0.831 6.8 6.1
information on the total number of CEB since we were SNNP 22.31 20.95 0.125 6.3 5.7
interested in examining the contribution of change in Emerging region 3.67 4.91 0.005
nuptiality pattern to fertility transition. Affar 1.33 0.67 0.002 5.9 6.4
A Poisson-based multivariate decomposition for the Somali 1.15 2.97 0.001 7.0 7.2
non-linear response model was employed to identify, Benishangul-Gumuz 0.99 1.02 0.001 6.4 6.2
quantify, and decompose the changes in fertility levels over Gambela 0.20 0.25 0.001 5.6 4.7
time. This method is particularly suited for analyzing count
data, such as the number of CEB. It allows for a robust Mainly urban region 4.34 5.87 0.001
decomposition of observed changes into contributions Harari 0.25 0.24 0.925 6.1 4.2
from different explanatory factors. By leveraging this Addis Ababa 3.66 5.14 0.001 4.2 2.2
approach, we could isolate and measure the relative Dire Dawa 0.43 0.49 0.6807 5.0 4.7
contributions of shifts in nuptiality patterns, such as age Religious affiliation
at marriage, PMS, and marital stability, as well as other Christians 67.16 68.75 0.114 6.4 5.5
covariates, to the overall fertility transition. In all our Non-Christian 32.84 31.25 0.114 6.6 6.5
analyses, sampling weights were applied to both descriptive
and decomposition analyses. (Contd...)

Volume 11 Issue 3 (2025) 5 https://doi.org/10.36922/ijps.5749