Population Policies and Programmes in Singapore

15. Future Population Trends

By: ROS Size: 6" x 9" J/No: 05-10631 Fonts: Eras, GarthGraphic 15 Future Population Trends INTRODUCTION An examination of the most plausible course of population trends in the future and the social and economic consequences of such trends are presented in this chapter. To do this, population projections need to be prepared on the basis of certain assumptions concerning the future course of migration, mortality and fertility, the three factors determining the rate of increase or decline in any population. In Singapore the future path of mortality movement is not difficult to decide, while the movement of fertility in the future is somewhat more problematic to resolve. It is of course quite impossible to reckon the flow of migration in the future, which depends primarily on the need for foreigners in the various sectors of the economy that is greatly dependent on external factors outside the control of Singapore. Three sets of population projections based on three different assumptions in regard to the future course of fertility have been computed to provide us with a better insight into the possibilities of the growth and structure of the population in the years ahead. In addition, we have constructed another population projection on the assumption that the total fertility rate will move up to the replacement level of 2.13 and remain at this level indefinitely. The results of this projection based on a somewhat unrealistic fertility assumption are only meant to illustrate the previously-mentioned concepts such as zero population growth, population replacement, and stationary population. METHODOLOGY The population projections were prepared by the component method which involves the separate projection of the number of males and 219 15 PP&P Pt 2/Ch 15 16/5/05, 3:11 PM 219 220 POPULATION POLICIES AND PROGRAMMES IN SINGAPORE females in each age group of the population.1 Since the base resident population in 2005 has been divided into quinary age group, the projections are computed for five-year intervals of time so that at the end of the five-year period all the survivors of one age group would have moved into the next older age group. Each cohort of the sex-age group is diminished to account for the impact of mortality over time. This step requires a set of five-year survival ratios (Px ) which are deemed to represent mortality in each cohort during specific-periods of time subsequent to 2005. A multiplication of the original number in each sexage group by the relevant survival ratio will give us the estimated number of persons five years older at a date five years later. A repetition of this procedure will yield the estimated population aged ten years older than those at the base date and at a date ten years later. The second step involves the essential task of estimating the future number of children born in each five-year time interval subsequent to the base date in 2005 in order to fill in the vacuum in the first age group 0–4 at periods of time five years later. To begin with, it is necessary to fix the most plausible assumption concerning the future course of fertility in terms of the total fertility rate with its equivalent age-specific fertility rates from age 15 to 49. These rates are then employed in conjunction with the female population in the reproductive age groups to derive the estimated number of births to the various five-year periods. The total births are split into male births and female births by applying the sex ratio at birth for the three-year period 2001–03. The number of births for each sex surviving at the end of a given five-year period is estimated by multiplying the number of births during the period with the survival ratio (Pb ). The three population projections were prepared on the assumption that the resident population is a closed one not subject to immigration and emigration. Mortality as measured by the life expectancy at birth is assumed to improve from 76.9 in 2005 to 77.7 in 2010 and to remain constant thereafter for the males, with the corresponding figure for the females improving from 80.9 in 2005 to 81.7 in 2010 and remaining constant thereafter for the females. In the case of fertility, three different assumptions are adopted to prepare the following projections. Low Projection: Fertility is assumed to increase from 1.33 in 2003 to 1.43 in 2005 and to remain constant thereafter...