Does working abroad cause less unemployment? Or is it actually harmful (directly or opportunity cost)? This question is from subjective origins but is (supposed to be) objective.
The context of this question arises from people in third world countries going abroad to work. Often they are seen as money-hungry people who don't 'love' their country (unless they are, say, physicists who do research abroad due to poor facilities or engineers or financiers simply looking for higher salary or something like that).
I was thinking that those people help their country through foreign remittances. I later additionally thought another help done is that whatever job they would have done in the country is likely ('likely' is probably the key word here) going to be replaced by someone else who would otherwise have been unemployed or underemployed would have that job which in turn likely (hooray key words) means that someone else who would otherwise have been unemployed or underemployed would have that job, etc.

If the answer is no (working abroad necessarily causes less unemployment), under what kinds of situations might this be the case?
If the answer is no (again, working abroad necessarily causes less unemployment) due to geographical variations, you may consider third world countries.


Edited to add: Also my concern is understanding whether or not like: are the ones going abroad necessarily like money-hungry people who do not 'love' their country or something? If you choose to work in your country, then do you necessarily 'love' your country more or 'serve' your countrypeople more than if you didn't work in your country? Of course 'love' and 'serve' are subjective, but it's like I wanna understand if somehow working abroad is like more beneficial to the individual but harmful to the country or something. To me, it seems like going abroad benefits everyone at least from 3rd to 1st world.
On remittances:
It is not unusual to hear about income being sent home by, say, US immigrants. However, the product of their labor and the side effects of their intellectual capital, sometimes called positive spillover, do not occur in the home country.  As such, they are not as beneficial to the home country as some counterfactual world where an equally profitable job existed at home. The immigrants are then beneficial to the host country.  The remittances still benefit the home country, however, and are particularly important when no employment is available at home.
On unemployment:
Broadly, immigration does not appear to have much of an impact on the unemployment in the host country. Or at least, something happens which masks that effect and makes it tremendously difficult to measure.  There has been a lot of controversy on this study but it helps highlight a lot of the issues if you take the chain of papers and responses seriously: https://www.jstor.org/stable/2523702?seq=1#metadata_info_tab_contents
On the type of people immigrating:
&quot;Are the ones going abroad necessarily like money-hungry people who do not love their country or something.&quot;  This isn't really the type of question economists answer. Everyone is money-hungry and equally self-interested, by default, and that is fine.  This helps (in some ways) avoid stereotyping immigrants. You may want to open another question about the types of people who like to immigrate.