Record number of US citizens are leaving the US to live abroad

[dpmapper]

But maybe Americans abroad just have fewer kids, or they are just not registering all of them with the Dept. of State because they are citizens of other countries ... which means the overall size of Americans abroad could be in line with the estimates.

How many of the citizens abroad are kids that were born in the US to non-citizen parents and then taken back to their home countries?  Birth tourism (i.e., the phenomenon of pregnant women coming on a tourist visa, staying for a couple months, giving birth, and then flying home) would be one egregious example of this.  

[dpmapper]

But maybe Americans abroad just have fewer kids, or they are just not registering all of them with the Dept. of State because they are citizens of other countries ... which means the overall size of Americans abroad could be in line with the estimates.

How many of the citizens abroad are kids that were born in the US to non-citizen parents and then taken back to their home countries?  Birth tourism (i.e., the phenomenon of pregnant women coming on a tourist visa, staying for a couple months, giving birth, and then flying home) would be one egregious example of this.  

Those would be registered within the US.

You asked why citizens abroad have fewer kids.  My question in response is perfectly relevant: how many of those citizens abroad are still minors (only US citizens due to loose citizenship-granting policies), and therefore much less likely to be giving birth?