Why is it 2.1 births per woman to sustain population levels?

Question

Why isnt it just 2? What factors make up the 0.1?

In: Other

Answer 1

Sometimes kids die before making it to reproductive age. It’s a sad truth but that’s why you need a little above 2 kids per couple in order to guarantee you can replace the current population and then some. To give concrete numbers, last year in the US 3.6 million babies were born. However, 37,000 children below the age of 18 died, or 1% of the number of children born.