Encyclopedia of Sociology

BIRTH AND DEATH RATES

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W. DAVID PIERCE

BIRTH AND DEATH RATES

Much of the birth and death information pub-
lished by governments is in absolute numbers.
These raw data are difficult to interpret. For exam-
ple, a comparison of the 42,087 births in Utah with
the 189,392 in Florida in 1996 reveals nothing
about the relative levels of fertility because Florida
has a larger population (Ventura et al. 1998, p. 42).

To control for the effect of population size,
analyses of fertility and mortality usually use rates.
A rate measures the number of times an event
such as birth occurs in a given period of time
divided by the population at risk to that event. The
period is usually a year, and the rate is usually
expressed per 1,000 people in the population to
eliminate the decimal point. Dividing Florida’s
births by the state’s population and multiplying by
1,000 yields a birth rate of 13 per 1,000. A similar
calculation for Utah yields 21 per 1,000, evidence
that fertility makes a greater contribution to popu-
lation growth in the state with the large Mormon
population.

BIRTH RATES

The crude birth rate calculated in the preceding
example,

( 1 )

X 1,000

Live births in year x

Midyear population in year x

Crude birth rate per 1,000=

is the most common measure of fertility because it

requires the least amount of data and measures

the impact of fertility on population growth. Crude

birth rates at the end of the twentieth century

range from over 40 per 1,000 in many African

countries and a few Asian countries such as Yemen

and Afghanistan to less than 12 per 1,000 in the

slow-growing or declining countries of Europe

and Japan (Population Reference Bureau 1998).

The crude birth rate is aptly named when

used to compare childbearing levels between popu-

lations. Its estimate of the population at risk to

giving birth includes men, children, and

postmenopausal women. If women of childbear-

ing age compose different proportions in the popu-

lations under consideration or within the same

population in a longitudinal analysis, the crude

birth rate is an unreliable indicator of the relative

level of childbearing. A portion of Utah’s 61 per-

cent higher crude birth rate is due to the state’s

higher proportion of childbearing-age women, 23

percent, versus 20 percent in Florida (U.S. Bureau

of the Census 1994). The proportion of childbear-

ing-age women varies more widely between na-

tions, making the crude birth rate a poor choice

for international comparisons.

Other rates that more precisely specify the

population at risk are better comparative meas-

ures of childbearing, although only the crude birth

rate measures the impact of fertility on population

growth. If the number of women in childbearing

ages is known, general fertility rates can be calculated:

( 2 )

X 1,000

Live births in year x

Women 15–44 in year x

General fertility rate per 1,000=

This measure reveals that a thousand women in

Utah of childbearing age produce more births in a

year than the same number in Florida, 89 versus 64

births per 1,000 women between ages fifteen and

forty-four (Ventura et al. 1998, p. 42). The 39

percent difference in the two states’ general fertili-

ty rates is substantially less than that indicated by