White women are also paid lesser than white men.
Black Africans and residents of rural provinces like the Eastern Cape also struggle to have access to medical aid and basic services like sanitation, water and the internet.
Economic inequality had decreased for Indians, Asians and whites, but remained fairly constant for coloureds and increased for black Africans.
Black African households in the Eastern Cape and Limpopo also get paid the least when employed.
This is according to the latest Stats SA report titled Inequality Trends in SA, which examined inequality across race and gender between 2006 and 2015.
Statistician-general Risenga Maluleke said the Eastern Cape, KwaZulu-Natal and Limpopo had a larger share of chronically poor households because of their large rural populations.
The report found that black Africans earned the lowest in their workplaces.
Eastern Cape and Limpopo residents had the lowest annual mean [money actually spent] and median expenditures.
On average, Eastern Cape and Limpopo residents living in urban areas spent R29,870 in 2006 and this rose to R40,290 in 2015.
Rural dwellers in both provinces spent R8,058 in 2006 and their average increased to R11,658 by 2015.
“Whites, in contrast, earned substantially higher wages than all other population groups.
“Their monthly average real earnings were more than three times higher than those of black Africans.
“Females were less likely to be employed and earned about 30% less on average as compared to males,” the report said.
“Overall, more rural provinces and black Africans tend to lag further behind in access to medical aid and basic services such as electricity, water, sanitation and internet,” Maluleke's report stated.
Centre for Risk Analysis chief economist Ian Cruickshanks said: “The country can only address this through free markets and not legislation.
“It’s a very emotive issue and difficult to pin down and say this is the cause.
“It’s also a question of what workers are prepared to accept and whether they're demanding more or not.”
The top 10% of the rich in the Eastern Cape have an expenditure that is six times bigger than the bottom 40% of the poor.
The bottom 40% in 2006 had 8.7% of all household expenditure, which decreased to 0.75% in 2015.
People living in the Eastern Cape also owned the least assets compared to other provinces in the same period.
The report said: “Regarding race, the white population group had the highest annual mean and median expenditure compared to other population groups [from 2006 to 2015], while black Africans had the least.
“Black Africans had an annual median expenditure of only R6,009 in 2006 and R9,186 in 2015.
“Meanwhile, the white population group had their annual median expenditure sitting at R77,308 in 2006, which increased to R100,205 in 2015.
“The annual median expenditure for whites was more than 10 times higher than that of black Africans across all four years.
“Furthermore, the white population group had more than nine times the annual mean expenditure of black Africans in 2006; though this ratio declined to more than seven times in 2015.”
Black African households in Limpopo (last) and the Eastern Cape (second last) have the lowest level of access to medical aid.