4. Houston, Texas (USA)
Projected 2016 GDP per capita, PPP: $77,343
Relying on blooming energy (mostly oil) industry, it doesn’t come as a surprise Houston ranks so high among the world’s richest cities. 6.3 million inhabitants metro is recording a healthy 1.6% GDP growth, which means $74,926 GDP PPP from 2014 are now $77,343.