Is it always bad if you continue to publish with your PhD advisor? What about the small country vs. big country bias? Is it any biased view from a viewpoint of a big country, where you have many chances to change laboratories/universities/working groups, vs. a small one?

Suppose you are from a small country when there is only one laboratory in your field and you want to stay in that country due to family reasons. Then you probably have these options:


stay there and get published with your supervisor;  
move to another country for some years and come back (and you will
end up with your supervisor);
move to related field and you will probably end up with    some sort
of collaboration with your supervisor anyway.


Are these options considered "weak" from an academic's perspective?
Do good work and publish in high impact journals. As long as you're doing good work, then it really shouldn't matter who you are publishing with. I don't think I've ever read a paper from a small country and had a preconceived notion about the quality of the work. However, if your lab becomes well known for a research area then I think that's a benefit and not a hindrance.