low-income countries more than a third of the population
is under age 15, while in high-income countries less than
a fifth is.
worlds population is growing by 200,000 people a
1980 and 2030, the population of low- and middle-income
countries will more than double -- to 7.0 billion, compared
with 1 billion for high-income countries.
the next 35 years, 2.5 billion people will be added to
the current population of 6 billion.
growth rate (PGR) is the increase in a countrys population
during a period of time, usually one year, expressed as
a percentage of the population at the start of that period.
It reflects the number of births and deaths during the period
and the number of people migrating to and from a country.
1980 and 2000 total world population grew from 4.4 billion
to 6 billion. By 2015, at least another billion people will
be added for a total of more than 7 billion. Chart
1 shows that most of this growth has been, and will
continue to be, in the developing world. In 1998, 85 percent
of the worlds peoplemore than 4 out of 5lived
in low- and middle-income countries; by 2015, it will be
6 out of 7.
trends in population growth rates
and birth rates
have declined over the past several decades. People are
living longer in both industrial
countries because of increased access to immunization,
care, and disease eradication programs. Many parents
are realizing that as health conditions improve, more of
their children are likely to survive, so they are choosing
to have fewer babies. Increased access to family
planning is helping parents control the number and spacing
of their children. In addition, with greater access to education
and jobs, more women are starting their families later and
are having fewer, healthier children.
to the slowing of birth rates, population growth rates have
started to decline in the many countries, although they
still remain high in some countries because birth rates
have not fallen as rapidly as death rates. As Chart
2 shows, population growth rate still tends to be higher
in low- and
countries than in high-income
countries. Even as the population growth rate has been
decreasing in these countries, the number of people added
to the population each year has been increasing because
the population base has become larger.