The Washington Post (December 23, 2022)
Millions of Americans have left the country. Where are they going, and why?
"The U.S. government does not keep a close count of Americans who have left the country; few governments do. The State Department asks some expatriates to register, but it does not maintain comprehensive, up-to-date directories. So, to count emigrants, we need a little help from our friends. Or at least from their statistical agencies.
The United Nations and World Bank collect data on foreign-born populations from local censuses and surveys all over the world, and use them to estimate migration patterns between more than 200 countries and localities. By their estimate, the population of American-born people abroad sat around 2.8 million as of 2020.
To keep their measurements consistent across countries and time periods — and to avoid double-counting millions of people with dual citizenship — they focus on just one measure of immigration: a foreign birthplace. Thus, they often leave out Americans who were born abroad to American parents, foreign-born spouses of Americans or naturalized American immigrants who later emigrated, even though many in those groups claim American citizenship. (They also typically don’t count American soldiers, tourists or temporary workers).
Consultants working for the Federal Voting Assistance Program (FVAP), an agency that helps Americans abroad cast their ballots, estimate that a total of about 4.8 million American civilians lived abroad in 2018. Consultants working with American Citizens Abroad, an advocacy group, estimated that there were about 3.9 million civilians, plus 1.2 million service members and other government-affiliated Americans."