Projecting ASFR using the Revised Sivamurthy's PC Model for Representing the ASFR Schedule

Applying the Statistical Technique of Principal Components Analysis to the schedules of Age-Specific Fertility Rates (ASFR) in Five year age groups for 74 countries around 1960, for 68 countries around 1970, and for 53 countries around 1980, Sivamurthy found that the First Two Principal Components accounted for about 90 percent of the total variation in observed ASFR, and the First Three Components accounted for 96–97 percent . Based on this analysis, Sivamurthy suggested a Two parameter Principal Components Model ( Sivamurthy’s PC Model) for representing ASFR schedule, which is shown to be useful in fertility estimation and projection. Since fertility situations have changed greatly in most of the countries in recent decades, Sivamurthy and Chetna applied the same PC Analysis to the ASFR schedules of 88 countries for the years around 2001, and found that the First Three Principal Components accounted for 92 percent of the total variation in ASFR. Based on this analysis Sivamurthy and Chetna suggested Revised Sivamurthy’s PC Model for ASFR schedule, which can be used for projecting ASFR. A simple procedure is suggested for estimating the three parameters of the Model. The procedure is applied to the Indian data for illustration.