This document defines key concepts in demography and population studies. It discusses how population size and composition can change due to factors like birth rates, death rates, and migration. It also introduces the demographic balancing equation that is used to track changes in a population over time based on births, deaths, and migration. Important demographic processes that influence population dynamics are also mentioned, such as fertility, mortality, and social mobility.

4.  Demography is scientific study of human
population.
 & Changes within them

5. OR in Population Size & its Composition
in response to:
 Birth
 Aging
 Death
 Migration

6. i Population size (# of persons in pop:)
rapid growth, slow growth, population decline
ii Population Structure: / Composition:
(Division according to characteristic)
(E.g:- Sex structure, Age structure)
ethnic, age, sex (also, how many are non-citizens)
iii Population distribution
% rural, % urban, % suburban. Also, how many
citizens live overseas
Important ‘demographic processes’ include:
fertility, mortality, marriage, education & social mobility.

7. 1960 1970 1980 1990 2000
US 179,323,175 203,211,926 226,545,805 248,709,873 281,421,906
Fl
4,951,560 6,789,443 9,746,324 12,937,926 15,982,378
Ln 74,225 103,047 148,665 192,493 239,452

8. Population Structure: / Composition:
(Division according to characteristic)
(E.g:- Sex structure, Age structure)
ethnic, age, sex (also, how many are non-citizens)
Males Females

9. Population distribution
% rural, % urban, % suburban. Also, how many
citizens live overseas

10.  No: of Live Births (B)
 No: of Deaths (D)
 No: of Immigration / In Migration (IM)
 No: of Emigration / Out Migration (OM)

11. Components of Population Change
(Population Dynamics)
• Demographers rely upon the “Demographic Balancing
Equation” to very simply and elegantly summarize
population change:
Pop2 = Pop1 + B – D + IM – OM, where
Pop2 = Population at a later time period
Pop1 = Population at an earlier time period
B = Births
D = Deaths Migration
Mortality
IM = In-Migration
Fertility
OM = Out-Migration
• The nature of population change is simple… changes can
only occur through: 1) Births, 2) Deaths, or 3) Migration

12. PUSH FACTORS: PULL FACTORS:
Unemployment Attracts the Migrants
Booming economy
Famine
Favorable Immigration
War
laws.
Political or Free Agricultural Land
Religious harassment

13. NI(B-D)+Net Migration(IM-OM)
Natural Increase:
Surplus or deficit of births over death
Net Migration:
Net effect of immigration & emigration ( or )

14.  Population is increased at a given period
of time.
 Effect of natural increase & net migration.
 Expressed in % per year.
 Rapid PGR link to following many problems in less
developed countries.
Hunger inadequacies in social / Health services
Poverty i,e Transportation & communication
High IMR

15. • Number of years it will take for population
to double at current growth rate
70 ÷ Growth Rate = Doubling Time
Growth Rate Doubling Time
Uganda 3.6% 19 years
Afghanistan 2.5% 28 years
India 1.3% 54 years
United States .5% 140 years
Denmark 0.0% --
Russia -0.5% 140 years* (1/2)

16. 1. Census
2. National Survey
3. Registration of vital events
(Births, Deaths ,Marriages , Adoptions, Divorces & separations)
4. Demographic Studies

17. END