Cantonese regions of China: Guangdong, HK, Macau, some areas in Guangxi. Many established overseas Chinese businesspeople are also Canto.
Mandarin: Anywhere else in Mainland China (Shanghai, Beijing, etc.). Many new Mandarin speaking people are starting their own businesses,
So if you take living conditions, etc. of these places and income and average them, who tend to be wealthier: Cantonese or Mandarin?