Define demography.
Demography is the scientific and statical study ofpopulation, populationchange, size, its components,process and other various related factors is calleddemography.
Write the differences between:
a. Fecundity and Fertility.
b. Natural and Artificial factor of population change.
c. Vasectomy and Minilap.
d. Net migration rate and Gross migration rate.
a. Fecundity and Fertility.
Fecundity | Fertility |
It is the biological capacity to participate in reproduction process. | It is the actual performance of reproduction. |
All fecund women aren't fertile. | All fertile women are fecund. |
It cannot be counted in number. | It can be counted in number. |
b. Natural and Artificial factor of population change.
Natural factor | Artificial factor |
It changes the population naturally. | It changes the population artificially. |
The natural cause of population change are natural disasters, etc. | The artificial cause of population change are migration, chemical disorder, etc. |
It is without people's knowledge. | It is with peoples' knowledge. |
c. Vasectomy and Minilap.
Vasectomy | Minilap |
It becomes effective in 6 to 8 weeks after surgery. | It becomes effective immediately after surgery. |
It does not need special equipment. | It requires expensive complex equipment. |
Medical are not seen. | There is a slight risk in eptopic pregnancy. |
It is contraception for males. | It is contraception for females. |
d. Net migration rate and Gross migration rate.
Net migration rate | Gross migration rate |
It is the difference between in-migration and out-migration. | It is the sum of in-migration and out-migration. |
NMR = I-O/P * 1000 | GMR = I+O/P * 1000 |
The calculated value of NMR can be negative or positive. | The calculated value of GMR can only be positive. |