FACTORS AFFECTING FACTORS AFFECTING POPULATION CHANGEPOPULATION CHANGE

There are four factors that affect There are four factors that affect population change in a country:population change in a country:

BIRTH RATEBIRTH RATE DEATH RATEDEATH RATE

IMMIGRATIONIMMIGRATION EMIGRATIONEMIGRATION

Birth RateBirth Rate

TThe number of live births per 1000 in he number of live births per 1000 in a year. a year.

Birth rates are affected by such Birth rates are affected by such factors as nutrition, fertility, attitudes factors as nutrition, fertility, attitudes about abortion, labour value of about abortion, labour value of children, government policies, social children, government policies, social value, the availability of value, the availability of contraception and culture.contraception and culture.

DEATH RATEDEATH RATE

The number of deaths per 1000 in a The number of deaths per 1000 in a year. year.

Death rates are affected by disease, Death rates are affected by disease, war, medical technology, improved war, medical technology, improved health care, transportation health care, transportation development and nutrition.development and nutrition.

IMMIGRATIONIMMIGRATION

        The number of people moving into The number of people moving into a country.a country.

  Pull factorsPull factors-characteristics of a -characteristics of a place that attracts people to it.place that attracts people to it.

EMIGRATIONEMIGRATION

The number of people leaving a The number of people leaving a countrycountry

Push FactorsPush Factors-characteristics of a -characteristics of a place that causes people to leave.place that causes people to leave.

RefugeesRefugees- people who are forced to - people who are forced to leave their country due to war, life-leave their country due to war, life-threatening discrimination, famine, threatening discrimination, famine, or natural disasters.or natural disasters.

Population Growth RatePopulation Growth Rate – The – The percentage increase in a population percentage increase in a population over a period of time.  Calculated by over a period of time.  Calculated by subtracting the number of deaths + subtracting the number of deaths + emigrants from the number of births emigrants from the number of births + immigrants.+ immigrants.

Replacement LevelReplacement Level – The number – The number of children required to keep the of children required to keep the population of a country constant, not population of a country constant, not taking migration into consideration.  taking migration into consideration.  This is about 2.1 children per female This is about 2.1 children per female in MDCs and 2.5 children per female in MDCs and 2.5 children per female in LDCs.in LDCs.

Total Fertility RateTotal Fertility Rate – The average – The average number of children a woman has in number of children a woman has in her lifetime in a country.  This her lifetime in a country.  This obviously depends on religion, obviously depends on religion, culture, social values and economic culture, social values and economic status.status.

  

Rate of Natural Increase (RNI) Rate of Natural Increase (RNI) – birth – birth rate minus death rate, calculated as a rate minus death rate, calculated as a percentagepercentage; this does not take migration ; this does not take migration into considerationinto consideration

   RNI (%) =    RNI (%) =    BR  -  DRBR  -  DR                                                          10 10    (in order to get a % you must divide by 10 (in order to get a % you must divide by 10

because BR and DR are measured per because BR and DR are measured per 1000)1000)

Doubling TimeDoubling Time – The time – The time in yearsin years needed for a population to double its needed for a population to double its size assuming the growth rate size assuming the growth rate remains the same.remains the same.

   DT (years) = DT (years) =    70__   70__                                                 RNIRNI