World Development Report 1984

vide accelerating decline early on (in some cases Table 2. Population composition
after a few years of constant fertility), followed by
decelerating decline as fertility approaches replace- The dependency ratio is the combined population
ment level. Fertility is assumed to remain at under fifteen and over sixty-four years as a perreplacement
level once it has been reached. centage of the population between those ages. The
The future path for mortality is based on the dependency ratio for 2000 is derived from the
assumption that increments to life expectancy standard World Bank population projections used
depend on the level reached. Changes in female in Table 1 of this Supplement and in Table 19 of the
life expectancies between 1965-69 and 1975-79 World Development Indicators.
were regressed on the initial life expectancies, separately
for two groups of countries: those with
female primary-school enrollment percentages Table 3. Contraceptive use and unmet need
under 70, and those with percentages of 70 or
more (including developed countries). Estimates Current use of contraception is expressed as the perof
one-year increments were obtained by dividing centage of currently married women aged 15-49
the estimated ten-year increments from these two using each method of contraception. For El Salvaequations
by ten. dor, Thailand, Guatemala, Jamaica, Korea, Pan-
Alternative projections build in more rapid fertil- ama, and Venezuela the base is currently married
ity and mortality decline. For rapid fertility decline women aged 15-44; for Kenya and Sudan it is
the future path of fertility is based on the experi- ever-married women aged 15-50. Sterilization
ence of eleven developing countries, including includes both male and female sterilization. Vaginal
China, Colombia, and Thailand, that have had methods include spermicides and the diaphragm.
rapid fertility decline since World War II. Once fer- Other methods include rhythm, withdrawal, abstitility
decline began in these countries, the total fer- nence, and in some cases douche and folk methtility
rate fell by a roughly constant amount-about ods. The sum of prevalence for each method may
0.2-every year. A constant linear decline at the not add to the total because of rounding.
average pace of these eleven countries provides Low and high estimates of unmet need for contrathe
path for rapid fertility decline, with the added ception are calculated only for women who want
proviso that decline ends when replacement level no more children; they do not include women who
is reached and fertility thereafter stays at replace- wish to delay a birth. The loul estimate includes
ment level. married women of reproductive age who want no
Summary measures for country groups may dif- more children, are not using any method of contrafer
from those in Table 19 of the Indicators because ception, and are exposed to the risk of pregnancy
projections were not computed for all countries. (that is, are fecund, not pregnant, not breastfeed-
For rapid mortality decline, a logistic curve was ing, or breastfeeding more than a year). The high
derived to represent the trend in life expectancy estimate includes, in addition to the above, those
among developing countries between 1960 and who are using less effective contraceptive methods
1980 (see the chart in Box 4.5). Fourteen countries (rhythm, withdrawal, and the like), as well as
that substantially outperformed this curve (and those breastfeeding less than one year.
had initial life expectancies above forty) were used Data for contraceptive prevalence and unmet
to derive a second logistic curve. This second curve need are all from nationally representative World
provided the time path for rapid mortality decline. Fertility Surveys (WFS) and Contraceptive Preva-
The rate of natural increase is the difference lence Surveys (CPS) for the years specified. The
between births and deaths per hundred popula- figures for contraceptive use may differ from fig-
.tion. Summary measures are weighted by popula- ures in Table 20 of the World Development Indication
in 1982. tors because more recent estimates, based not on
The total fertility rate represents the number of surveys but on family planning program statistics,
children that would be born to a woman if she are included there. Figures in italics refer to earlier
were to live to the end of her childbearing years years than stated: Bangladesh (1979), Sri Lanka
and were to bear children at each age at prevailing (1975), Tunisia (1978), Jamaica (1975-76), Panama
age-specific fertility rates. The rate for 2000 is given (1976), and Mexico (1978). Surveys in three coununder
the assumptions of both standard and rapid tries did not achieve national coverage: Sudan
fertility decline. Summary measures are weighted (northern population only); Mauritania (sedentary
by 1982 population. population only); and Malaysia (peninsula only).
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