In 2009, the percentage of the planet's population living in urban areas crossed the 50% thresholdâ¦this year the population of the world's cities will grow by a further 65 million people, equal in size to the total population of Franceâ¦
As recently as 1990 the United States had the highest number of one million plus inhabitant urban agglomerations globally with a total of 33â¦.by the year 2020 China will lead the world with 121 followed by India with 58â¦
Remarkably, in 2009 China generated some 40.9% of GDP from just 16.6% of its population living in the 35 largest cities.
From an interesting Credit Suisse report, Opportunities in an urbanizing world (pdf).