Why is the replacement fertility rate 2.1 instead of 2.0?

[swampwiz]

What is the reason for this? Does it have something to do with the fact that the women who don't have any children somehow contribute more to the statistic than women who do have children?

 

[Ygggdrasil]

It accounts for the children who die before they have the chance to reproduce.

 

[Orodruin]

A corollary of #2 is that this rate depends on the situation. While developed countries will be close to 2, undeveloped countries will need higher rates.

 

[swampwiz]

It accounts for the children who die before they have the chance to reproduce.

OK, this makes sense - but shouldn't those non-survivors count as simply folks that go childless, and therefore be included in the denominator?

 

[Orodruin]

OK, this makes sense - but shouldn't those non-survivors count as simply folks that go childless, and therefore be included in the denominator?

No, by definition the fertility rate is the expected number of children of a woman who lives to the end of her reproductive life.

 

[rootone]

OK, this makes sense - but shouldn't those non-survivors count as simply folks that go childless, and therefore be included in the denominator?

People who don't reproduce still are people, they can't be reasonably considered as nonexistent.

 

[Tom.G]

OK, this makes sense - but shouldn't those non-survivors count as simply folks that go childless, and therefore be included in the denominator?

How can you count someone that hasn't survived? (no longer exists.)

 

[Gigaz]

The sex ratio at birth for humans is 1.05 males to 1 female at birth on average. So for 2.1 children there will be 1.076 males and 1.024 females. I guess this is the main contribution.