Encyclopedia of Sociology

BIRTH AND DEATH RATES

risk to dying are more accurate. Unlike fertility,
however, the entire population is at risk to dying,
and this universal experience happens only once
to an individual.

The impact of mortality on population growth
can be calculated with a crude death rate:

( 5 )

X 1,000

Deaths in year x

Midyear population in year x

Crude death rate per 1,000=

Crude death rates vary from over 20 per 1,000 in
some African countries to as low as 2 per 1,000
(Population Reference Bureau 1998). The lowest
crude death rates are not in the developed coun-
tries of Europe, North America, and Oceania,
which have rates between 7 and 14 per 1,000.
Instead, the lowest crude death rates are found in
oil-rich Kuwait, Qatar, and United Arab Emirates,
where guest workers inflate the proportion of
young adults, and in the young populations of
developing countries experiencing declining mor-
tality. Developed countries that underwent indus-
trialization and mortality decline before 1950 have
old-age compositions. The proportion of people
age sixty-five and over ranges between 11 and 17
percent in these countries compared to less than 5
percent in most African, Asian, and Latin Ameri-
can populations. Although there is a risk of dying
at every age, the risk rises with age after childhood.
Consequently, older populations have higher crude
death rates.

To control for the strong influence of age on
mortality, age-specific rates can be calculated for
five-year age groups:

( 6 )

X

1,000

Deaths in year x to the population age a

Population age a in year x

Age-specific mortality rate per 1,000=

Before age five, the age-specific mortality rate
usually is subdivided to capture the higher risk of
dying immediately after birth. The rate for one- to
four-year olds, like other age-specific rates, is based
on the midyear estimate of this population. The
conventional infant mortality rate, however, is
based on the number of live births:

( 7 )

X 1,000

Deaths under age 1 in year x

Live births in year x

Infant mortality rate per 1,000=

The infant mortality rate is often disaggregated

into the neonatal mortality rate for the first month

of life and the postneonatal rate for the rest of

the year.

( 8 )

X 1,000

Deaths under 29 days of life in year x

Live births in year x

Neonatal mortality rate per 1,000=

( 9 )

X 1,000

Deaths from 29 days to age 1 in year x

Live births in year x

Postneonatal mortality rate per 1,000=

Infant mortality varies widely throughout the

world. Iraq, Afghanistan, Cambodia, and many

African countries have 1998 rates that still exceed

100 per 1,000 live births, although most have

declined (Population Reference Bureau 1998). In-

fant mortality rates in most other African, Asian,

and all other Latin American countries have de-

clined as well. They now range in developing

countries from 7 in Cuba to 195 in Sierra Leone.

In contrast, developed countries have rates at or

below 10, led by Japan with under 4 infant deaths

per 1,000 live births.

The declining American infant mortality rate,

7 per 1,000 live births in 1998, continues to lag

behind Japan, Australia, New Zealand, Canada,

and most Northern and Western European coun-

tries due to a higher prevalence of prematurity

and low-birth-weight babies which are major causes

of infant death (Peters et al. 1998, pp. 12–13). The

prematurity and low-birth-weight rates for the coun-

try’s largest minority, African Americans, are dou-

ble those of non-Hispanic whites (Ventura 1998,

pp. 57–58). Not all minority mothers have higher

rates than non-Hispanic whites. Low-birth-weight

rates are lower for Americans of Chinese, Mexi-

can, Central and South American origin, about the

same for Native Americans and those of Cuban

origin, and higher for Puerto Rican, Filipino, and

Japanese Americans.