Where is the fastest growing city in the world?

Is the planet's fastest growing metropolis in China, Indonesia or Niger? With many different methods of measurement, there's no simple, single answer

The fastest growing city in the world is Batam in Indonesia " or Niamey in Niger " or maybe Xiamen in China. It all depends on who you ask.

Batam is the fastest-growing city in the world by population, according to US-based consultancy Demographia, which bases its annual Demographia World Urban Areas ranking largely on the United Nations' 2010-20 world population forecasts - but only includes cities with a population of 1 million or more. Batam is close to Singapore and operates as a transport hub and industrial area, while a free-trade zone boosts trade with the island city-state. Batam had a population of 1.1 million in the latest estimate, with an annual growth of 7.4%.