China and India have lifted at least 125 million out of slums between 1990 and 2010.
* the number of people living in slums rose from 777 million in 2000 to 830 million in 2010. Unless urgent steps are taken, UN-HABITAT warned, that number could rise to 900 million in 2020 (Since there was net migration out the increase is from births inside slums)
State of the World's Cities 2010/2011 - Cities for All: Bridging the Urban Divide (UN report)
* the top 25 cities accounted for roughly 15% of the world’s GDP in 2005. This share increases to around one-quarter of the world’s GDP when the top 100 cities are included
* In India and China, the five largest cities were about 15% of national GDP in 2004, which was roughly three times what could have been expected based solely on their relative shares of the population