Financial systems and development

and Vital Statistics Report, World Bank country data, started to dedine (fertility transition), this trend is
and national censuses and surveys.
assumed to continue. It has been observed that no
The net reproduction rate (NRR), which measures country with a life expectancy of less than 50 years
the number of daughters a newborn girl will bear experienced a fertility decline; for these countries
during her lifetime, assuming fixed age-specific the average decline of the group of countries in
fertility and mortality rates, reflects the extent to fertility transition is applied. Countries with
which a cohort of newborn girls will reproduce below-replacement fertility are assumed to have
themselves. An NRR of 1 indicates that fertility is constant total fertility rates until 1995-2000 and
at replacement level: at this rate women will bear, then to regain replacement level by 2030.
on average, only enough daughters to replace International migration rates are based on past
themselves in the population.
and present trends in migration flows and migra-
A stationary population is one in which age- and tion policy. Among the sources consulted are estisex-specific
mortality rates have not changed over mates and projections made by national statistical
a long period, while age-specific fertility rates have offices, international agencies, and research instisimultaneously
remained at replacement level tutions. Because of the uncertainty of future migra-
(NRR=1). In such a population, the birth rate is tion trends, it is assumed in the projections that
constant and equal to the death rate, the age struc- net migration rates will reach zero by 2025.
ture is constant, and the growth rate is zero.
The estimates of the size of the stationary popu-
Population momentum is the tendency for popula- lation and the assumed year of reaching
tion growth to continue beyond the time that replacement-level fertility are speculative. They
replacement-level fertility has been achieved; that should not be regarded as predictions. They are inis,
even after the NRR has reached 1. The momen- cluded to show the implications of recent fertility
tum of a population in any given year is measured and mortality trends on the basis of generalized
as a ratio of the ultimate stationary population to assumptions. A fuller description of the methods
the population of that year, given the assumption and assumptions used to calculate the estimates
that fertility drops to replacement level by that will be available from the World Bank's forthcomyear
and remains there. For example, the 1990 ing World Population Projections, 1989-90 edition.
population of India is projected to be 848 million. If
the NRR were to drop to 1 by 1990, the projected Table 27. Demography and fertility
stationary population would be 1,448 millionreached
in the middle of the twenty-second The crude birth and death rates indicate respectively
century-and the population momentum would be the number of live births and deaths occurring per
1.7. thousand population in a year. They come from
A population tends to grow even after fertility the sources mentioned in the note to Table 26.
has declined to replacement level because past The percentage of women of childbearing age prohigh
growth rates will have produced an age distri- vides a more complete picture of fertility patterns.
bution with a relatively high proportion of women Comparison of 1965 and 1987 data adds an interin,
or still to enter, the reproductive ages. Conse- esting aspect to the pattern of reproduction during
quently, the birth rate will remain higher than the the past two decades. Childbearing age is generally
death rate, and the growth rate will remain posi- defined as 15 to 49.
tive for several decades.
The total fertility rate represents the number of
Population projections are made component by children that would be born to a woman if she
component. Mortality, fertility, and migration are were to live to the end of her childbearing years
projected separately and the results are applied it- and bear children at each age in accordance with
eratively to the 1985 base year age structure. For prevailing age-specific fertility rates. The rates
the projection period 1985 to 2005, the changes in given are from the sources mentioned in Table 26.
mortality are country specific: increments in life The percentage of married women of childbearing age
expectancy and decrements in infant mortality are using contraception refers to women who are pracbased
on previous trends for each country. When ticing, or whose husbands are practicing, any form
female secondary school enrollment is high, mor- of contraception. Contraceptive usage is generally
tality is assumed to decline more quickly. Infant measured for women age 15-49. A few countries
mortality is projected separately from adult mortal- use measures relating to other age groups such as
ity. 15 to 44, 18 to 44, and 19 to 49.
Projected fertility rates are also based on pre- Data are mainly derived from the World Fertility
vious trends. For countries in which fertility has Surveys, the Contraceptive Prevalence Surveys,
243