The new black middle class could be at risk of slipping back into the ranks of the proletariat if the government does not mastermind an economic turnaround. One in 10 South Africans is now believed to be middle class, according to the Institute of Race Relations. But the problem, it points out, is that these class newbies are vulnerable to an economic downturn or rising interest rates."First-generation middle-class members can't afford to lose assets. If they are retrenched or lose their jobs they can't fall back on other family members within the middle class for assistance," said Gabriela MacKay, a research analyst at the institute.She said the black middle class had grown rapidly over the past two decades. For her study, she relied on a number of indicators to measure class structure, including household spending, education levels, broadband internet usage and property ownership.The growth of the black middle class could be shown by the fact that in 2004 only 9.1% of blacks were members of medical aids, but 10 years later this had grown to 12.4%, MacKay said.One of the reasons for this growth spurt was the growth of the public service, she said.For the middle class to continue to expand, economic growth was essential.The demise of the black middle class would have a negative effect on the country."They are the driving force in the economy, and it is a sign that the economy is working."The middle class were less inclined to support populist parties.The CEO of the institute, Frans Cronjé, said: "The post-1994 government has done better, but too many areas of policy still undermine the educational outcomes, ent-repreneurship and investment-driven growth that is so important to unlocking access to the middle classes."..