This paper uses a unique natural experiment in Chinese villages to investigate whether access to telecommunications-- in particular, landline phones -- increases the likelihood of outmigration. By using regional and time variations in the installation of landline phones, the difference-in-differences estimation shows that access to landline phones increases the ratio of out-migrant workers by 2 percentage points, or about 50 percent of the sample mean in China. The results remain robust to a battery of validity checks. Furthermore, landline phones affect outmigration through two channels: information access to job opportunities and timely contact with left-behind family members. The findings underscore the positive migration externality of expanding telecommunications access in rural areas, especially in places where migration potential is large.That is from this paper by Yi Lu, Huihua Xie, & Lixin Colin Xu.
Landline phones is not be the first thing that comes to mind as a determinant of migration. It is surprising to see how significant that is though, and it makes sense. Leaving home knowing that one can keep in touch with relatives makes a difference. I can't imagine how it feels to leave family behind knowing that communication will be very difficult, and that is precisely the situation that many immigrants have faced. Phones reduce the costs of leaving.
If we follow the argument we should see an increase in outmigration from poor regions due to cheaper Internet communication. Internet however have other effects such as outsourcing which increases employment in developing countries and as a consequence might reduce outmigration.