TFR and migraion

Total Fertility Rate (TFR)

TFR : average number of children born per woman

for a population to remain the same, the TFR must be 2.1 (because some children can't live long)
higher than 2.1 - population rises
lower than 2.1 - population falls

World TFR : 2.42 (two years ago - 2.59/ last 2.47)
U.S. 2.01 (last year - 2.06)
Nigeria 6.89
Japan 1.40 (a lot of old people and no children)

Total rate : zero

Net migration rate : the difference between the number of persons entering and leaving a country during a year

an excess of persons entering the country is net immigration

- written as a positive number
- example :
Canada has 5.65 migrant per 1000 population
U.S. 2.45 (it was 3.62 last year)

an excess of persons leaving the country is net emigration

- written as a negative
- example :
Mexico has -1.68 migrants per 1000 population
                   -3.61 migrants two years ago and -3.11 migrants last year per 1000 population

Mr. Schick I didn't go to school last Friday, so I didn't write last blog.