Sir Stephen, a former member of the Bank of England Monetary Policy Committee, did however say there was «quite a lot of evidence that the differential in job opportunities, the differential in pay, is a
significant factor in
migration flows... around the world.»
Significant advances have been made in quantifying the nature of ground - water and petroleum
migration in basins over geologic time scales and relating these
flows to varied geochemical processes and tectonic forces (Garven, 1995).