Abstract:
This study explores the use of
exible link functions in discrete survival models
through a simulation study and an application to the Swaziland Demographic and
Health Survey (SDHS) data. The objective of the research study is to perform simulation
exercises in order to compare the e ectiveness of di erent families of link
functions and to construct a discrete multilevel survival model for age at rst marriage
among women in Swaziland using a
exible link function. The Pareto hazard
model, Pregibon and Gosset families of link functions were considered in models with
and without unobserved heterogeneity. The Pareto model where the family parameter
is estimated from the data was found to outperform the other models, followed by the
Pregibon and the Gosset family of link functions. The results from both simulation
study and real data analysis of the SDHS data illustrated that, misspecication of the
link function causes bias on the estimation of results. This demonstrates the importance
of choosing the right link. The ndings of this study reveal that women who are
highly educated, stay in the Manzini and Shiselweni region, those who reside in urban
areas were more likely to marry later compared to their counterparts in Swaziland.
The results also reveal that the proportion of early rst marriages is declining since
the di erence among birth cohorts is found to be very high, with women of younger
cohorts getting married later compared to older women.
