Editing Zero population growth (section)

== Definition ==
The [[population growth|growth rate of a population]] in a given year equals the number of births minus the number of deaths plus [[immigration]] minus [[emigration]] expressed as a percentage of the population at the beginning of the given year.<ref name=":0">{{Cite web |last1=Haupt |first1=Arthur |last2=Kane |first2=Thomas T. |last3=Haub |first3=Carl |date=2011 |title=PRB's Population Handbook |url=https://www.prb.org/wp-content/uploads/2011/09/prb-population-handbook-2011.pdf |website=Population Reference Bureau |pages=29–30}}</ref>

For example, suppose a country begins a year with one million people and during the year experiences one hundred thousand births, eighty thousand deaths, one thousand immigrants and two hundred emigrants. 

{{In5|10}}Change in population = 100,000 – 80,000 +1,000 – 200 = 20,800

{{In5|10}}Population growth rate = (20,800 ÷ 1,000,000) x 100% = 2.1%

Zero population growth for a country occurs when the sum of these four numbers – births minus deaths plus immigration minus emigration - is zero.

To illustrate, suppose a country begins the year with one million people and during the year experiences 85,000 births, 86,000 deaths, 1,500 immigrants and 500 emigrants.          

{{In5|10}}Change in population = 85,000 – 86,000 + 1,500 – 500 = 0

{{In5|10}}Population growth rate = (0 ÷ 1,000,000) x 100% = 0%

For the planet Earth as a whole, zero population growth occurs when the number of births equals the number of deaths.