New Economist Blog has a few posts on migration. The postSkilled migration boosts innovation discusses paper of Jennifer Hunt: "In this paper I have demonstrated the important boost to innovation per capita provided by skilled immigration to the United States in 1950-2000. A calculation of the effect of immigration in the 1990-2000 period puts the magnitudes of the effects in context." I thought that I noticed this and also in a few cases that I know the immigrants seem to perform better in adopted countries than their native countries. I do not have any real evidence for the second part of the statement except a few cases.
The second is about How rural villages have gained from China's great migration
and a third is about Why people emigrate.
In Rural Development of India , Malapati Raja Sekhar draws attention to a Business India report Urbanisation of rural India which may have implications to urban migration .