Mathematical Modeling of Age-Specific Fertility Rates of Nepali Mothers: A Polynomial Approach

In this paper, polynomial models have been formulated to describe the distribution pattern of age-specific fertility rates (ASFRs) and forward-cumulative ASFRs of Nepali mothers. The former follows the bi-quadratic polynomial and the latter follows the quadratic one. Velocity and elasticity equations of the fitted models have been formulated. The areas covered by the curves of the fitted models have been evaluated, and the area covered by the curve of ASFRs is equivalent to the total fertility rate (TFR). The elasticity curve of ASFRs helps to measure the sensitivity of ASFRs to the age of women at the birth of a child. Furthermore, the mode of the fitted ASFRs has been estimated. To test the stability and validity of fitted models, cross-validation prediction power, shrinkage of the model, F-test statistics, and the coefficient of determination have been applied. All the test statistics suggest that the proposed models are significantly fit the ASFRs.