The mobility and migration of the highly skilled in knowledge-based economies is interwoven in complex ways with flows of knowledge. Hughes (2007) PHG 31, 4 summarizes the literature. Park (2003) Papers Reg. Sci. 82, 2 demonstrates that the internet has greatly contributed to the diffusion of codified knowledge and technology to China and the Asia Pacific Rim, but the distribution of knowledge is spatially uneven. Thus, he argues (2004, PHG 28, 3) ‘we should not abandon policies to reduce the disparity in the knowledge-based economy’. Egger et al. (2007) Ann. Reg. Sci. 41 introduce factor mobility in the knowledge-capital model to explain why European nations are less specialized than US regions.