But where recent economic booms had been strongest, and where the inflow of migrants had reached record highs, the prospects for a sharp decline are clear. This is particularly the case in western Europe. Ireland and Spain, both historically countries of emigration, have seen massive arrivals of foreigners in the past decade. Romanians, in particular, flocked to man Spain’s building boom; Poles and Lithuanians went to Ireland. Britain has drawn an exceptionally large number of migrants from Europe’s east, especially Poland; Greece attracted Albanians; Italy drew in Romanians and others. The rush of people on the move went hand-in-hand with the expansion of low-cost travel in Europe, especially by air.
Now some of these flows are slowing, even reversing. A study by the Institute for Public Policy Research (IPPR), a British think-tank, this year noted that of the 1m or so East Europeans who came to Britain since 2004, around half have already left—some for better economic prospects back home, others because they intended to stay only to learn English or to work temporarily, or because they wish to return to their families. The inflow of migrants to Britain from this region has also dropped sharply, by 17% last year. Danny Sriskandarajah of the IPPR concludes that “After one of the most intense periods of migration there has to be a natural end. The dominoes are starting to fall.”
An increasingly spiky world may be going flat. Return migration wouldn't be feasible without at least some leveling of the economic landscape. But the main concern should be how spiky hot spots are being starved for talent by the countries that host these world cities.
You call this phenomenon "the revenge of the valleys of globalization." Economic outliers who refuse to move are not inclined to support policies that will further erode their own wellbeing. That should bode well for the brain drain countries as talent completes the journey of brain circulation. Will native OECD human capital follow them?