Highly Educated People are Becoming More Concentrated in Big Cities

I quote from an article by Ugne Saltenyte in Euromonitor International:

With governments recognising the link between education and economic competitiveness, education standards are rising globally. Increased prioritisation of primary and secondary education is translating into rising uptake of tertiary education in many economies. The number of people with higher education globally rose from 518 million in 2005 to 704 million in 2013, with 24% of the latter amount being concentrated in the top 100 largest metropolises worldwide. To put this into perspective, these metropolises accounted for just 11% of the global population in 2013.

In the early stages of economic development, people living in rural areas move to urban areas in large numbers. They do so because they can earn more and live better by doing so, but that in turn depends on their producing more in the city on average than they could in the countryside. Thus the rural-urban migration -- done in the early stages of economic development by people who have relatively little formal education and who will work in relatively unskilled jobs in the towns and cities -- has led to an period of relatively rapid increase in GDP. This motor for economic growth clearly only functions for a while, since eventually the rural-urban migration diminishes for lack of rural population to migrate.

I would guess that it is in the largest cities that the most educated people can find the best jobs and most improve their lives, because it is there that they can be most productive. Thus the increase in education and the increasing concentration of the highly educated in centers of productivity in "the new knowledge society" should also yield increases in GDP growth rates -- at least for a while.