As Dr Johnson said, the sight that most excites a Scotsman is the road down south to England, one taken by my family. Conan Doyle had a very interesting paper on this. What it boils down to is that abler and more creative people gravitate to the larger and more important economically developed urban areas.

For some very interesting work on the link between migration flows and FDI see ‘Migrant networks and Foreign Direct Investment' available at http://users.ox.ac.uk/~econ0247/Migration.pdf (JDE). The paper by Driffield and Jones (2013, European Journal of Development Research), looking at the impact of FDI, and migrant remittances on economic growth, could also be helpful to you. I hope this helps.

Sassen's 1988 The Mobility of Labour and Capital and Jonathan Crush's 1991 South Africa's Labor Empire, albeit not framed in  terms of North and South, are still great starting points

more recent references would be 

Fernández Kelly and Massey's 2007 article on the Annals of Political Science v.610 2007, 'Borders for whom'

Ferguson and McNally's 'Precaurious Migrants' in the Socialist Register 51, 2015

or, in a different direction, 

World Bank economist lans pritchett's 'let their people come', and parts of the World Bank 2009 World Development Report

I have just come acroos a new NBER working paper (No. 219847 "Migrants, Ancstors and Investment") which might be of your interest.