Maybe there is another reasons to why some never attend international conference that peers in other countries like EU and US doesn't have. Visa issues and lack

Maybe there is another reasons to why some never attend international conference that peers in other countries like EU and US doesn't have. Visa issues and lack of travel funding. I know a lot of researchers in the US who never went into an international conference although they are on average the best funded compared to other countries. And they don't have to suffer for visa appointments that can take months and you can get it after the conference very commonly.