Purpose and Perspective¶
Total Fertility Rate (TFR) is endogenously represented in iSDG in order to capture the effect of changes in socio-economic development on demographics. Since various factors can influence reproductive behavior at different ages, in this sector age-specific fertility is calculated.
The Fertility sector is based on an extensive review and synthesis of demographic literature and the findings of the 1994 International Conference on Population and Development  as they relate to fertility modeling. Births, the final output from the sector, are calculated on the basis of the number of sexually active women in the fertile age cohorts (15 to 49), the total fertility rate (TFR), and the age-specific fertility distribution.
Sector Structure and Major Assumptions¶
Exogenous Input Variables¶
Age Specific Fertility Distribution - Units: Dmnl/Year
Initial Contraceptive Prevalence Rate - Units: Dmnl
Initial Desired Number Of Children Per Woman - Units: Dmnl
The iSDG model distinguishes between two types of fertile females, those who use birth control and those who do not. The size of each group is determined by the size of female population cohorts and by the variable proportion using conscious fertility control. Both of these variables change over time. The fertility rate of those who use birth control matches the desired family size, while the fertility rate of those who do not use birth control matches the unconsciously determined fertility rate.
Footnotes and References¶
 Birdsall, N. ,1988, Economic Approaches to Population Growth. Handbook of Development Economics. T. N. S. H. Chenery. Amsterdam, Elsevier Science Publishers B.V. 1: 478-542.
 Cypher, J. M. and J. L. Dietz, 2004, The Process of Economic Development. London, Routledge.