1. Pof. Dr Devi Bahadur Thapa

2. Demography Demography is the scientific study of human population It is derived from two Greek words:  Demos = people  Graphien = to draw, describe

3. It deals with three observable human phenomenon : a) changes in population ( growth and decline) b) Composition of population and c) Distribution of population in space Thus demography refers to scientific study of population with respect of size, structure and growth

4. Definition Peter R. Cox defined demography as “ Demography is the statistical method of studyin human population involving the measurement of size, growth and decrease of the number of people.”

5. Sources of Population Data 1) Population census 2) Civil (Vital) Registration system 3) Sample Survey

6. Factors of Demography i. Fertility ii. Mortality iii. Migration

7. Fertility Fertility is the reproductive function and mainly related to women’s reproductive process It is directly related to number of babies a women gives birth during her life Fertility is obtained in following ways a) Crude Birth Rate (CBR) b) General Fertility Rate (GFR) c) Age Specific Fertility Rate (ASFR) d) Total Fertility Rate (TFR)

8. Fertility Crude Birth Rate (CBR) It is the ratio of total number of living infants born within a year to the total number of population of mid-year (1 st July) per thousand CBR = (live birth in a year/ total population of that year) X 1000

9. Fertility General Fertility Rate (GFR) it is the number of infants (live birth) of a year from the mother of child bearing age group (15-49) per thousand GFR = (number of live birth in a year/ mid year population of women age 15-49) X 1000

10. Fertility Age Specific Fertility Rate (ASFR) Age specific ferrtility rate shows the reality that of women of 15-49 age group, what age group of women bears more infants and what age group bear less ASFR = (number of living infants born from woman of specific age group with in a year/ the number of woman of same age group of mid year) X 1000

11. Fertility Total Fertility Rate (TFR) it indicates how many infants are born on average by a women or an age group of woman during the period of 15 to 49 years. It is derived from age-specific fertility rate TFR = (sum of age specific fertility rate X 5 age interval)/ 1000

12. Example : The number of births occurred in Nepal in 1958 is shown below classified according to age of mother together with female population in each group of child bearing period The total population of Nepal in 1958 was 228580. determine a) Crude Birth Rate ( CBR) b) Age Specific Fertility Rate (ASFR) c) General Fertility Rate (GFR) d) Total Fertility Rate ( TFR) Age15-1920-2425-2930-3435-3940-4445-49 Female population 8479070010726607592075100716206660 No of biths23431454116736102185134142293