The recent McKinsey Quarterly Chart Focus was on the shift on the global economy's center of gravity. There has been a number of articles written on this subject but the interactive map from McKinsey Quarterly's website give a graphical interpretation as to the population centers and where economic power projection will becoming from.
Global cities will predominate and economics activities from these huge megalopolis will also mean several things:
1. Economies of scale in products and services, as transportation over long distance could be optimized
2. Any type of threats would be magnified as densely populated cities means that more people would be affected if there were any form of large-scale catastrophe
3. Governments need to sensitive to the demographics and population migration patterns, economic well-being of their citizens
It would be interesting to watch and keep track of the trends and events that follow in the coming decades.