Page 14 - Health, Population and Environment Education 10

Demographic Measurement
The mathematical representation of demographic
components is called demographic measurement. It is
presented in rates and ratios. Different statistical tools
and mathematical formulae are used in demographic
measurements. They show birth, death and migration
in numerical figures. It means that the increase and
decrease of population in a place are shown in numerical Fig: 1
figures by demographic measurements. Fertility rate,
mortality rate and migration rate are regarded as demographic measurements. We can
analyze population size, structure, distribution, composition by means of demographic
measurements. Analyzing population data supports to know population situation as well
as trend of future population in a place.
Fertility and Fecundity

Fertility
Fertility is the actual birth performance of a female or total children given birth by female
during the reproductive period. If a female has given birth to five children during her
reproductive period (15 - 49) years, her fertility is regarded as 5. Since, only the females
give birth to children, it is related only with females. Those females who give birth to
children are called fertile women.
Fecundity
Fecundity is the capability of male and female to take part in reproduction. It is the biological
and physiological potentiality to bear children. It is related to both male and female. Females
have generally starting of menstruation at the age of 15 years which is called menarche The
menstruation generally stops at the age of 49 years which is called menopause. Females
are capable of bearing children only from menarche till menopause. Hence, their fecundity
remains from 15 to 49 years. Males can make females pregnant after the production of sperms
in their body. Generally sperm production starts at the age of 13 years in males and may
continue till 70/80 years as well. It means that males have more fecundity. But, fecundity varies
from individual to individual. It differs among own siblings and even among twins as well.
The differences between fertility and fecundity are shown in the following table:
Fertility Fecundity
1. Fertility is the actual birth 1. Fecundity is the capacity of male and female
performance of a female. to take part in reproduction.
2. It is related only with females. 2. It is related with both males and females.

3. It is less than fecundity. 3. It is more than fertility.
4. Every fertile women are fecund. 4. Every fecund women may not be fertile.
5. It increases population directly. 5. Simply fecundity doesn’t increase population .
6. It is the effect. 6. It is the cause.

14 GREEN Health, Population and Environment Education Book-10