Gross value added (GVA) measures the contribution to an economy of an individual producer, industry, sector or region, according to the Financial Times. The attached map shows the GVA of municipalities in South Africa in a 3D format. As expected, metropolitan municipalities have a higher GVA than local municipalities. In 2013, the City of Johannesburg had the highest GVA in South Africa, followed by City of Cape Town, City of Tshwane, Ekurhuleni, Nelson Mandela Bay, Mangaung and Buffalo City. There is a very strong positive correlation between GVA, total population density and housing needs in South Africa, i.e. the stronger the economy of a municipality, the higher the population density and the higher the housing need.