Are there any statistics (or at least reasonable estimates from research) on how many USA citizens emigrated to "socialist" countries?
I'm not looking for a precise #, an estimate of an order of magnitude if perfectly fine.
UPDATE Just to be clear - I was using the official definition of "emigration" (e.g. from Google):
the act of leaving one's own country to settle permanently in another
In other words, people who merely move to a country temporarily for a specific job (like B1B visas in US), are not included in this definition.
For the purposes of this question, "socialist" simply means countries whose government officially called their socioeconomic system "socialist", e.g. USSR, PRC, Venezuela post-Chavez, Cuba post-Castro, Eastern Europe while still in Warsaw block, etc...).
To avoid subjectivity, i'm happy to take "official Wiki list" - List of socialist States.
I'm open to answers covering any timeframes starting from 1917, but the emigration must be only during the time period when the state was actually socialist according to Wiki timeline, e.g. post-1993 Russia does not count.