The social polarisation hypothesis argues that deindustrialisation causes the polarisation of the occupational structure, which in turn causes the income polarisation of the employed workforce of global cities. A central argument is that social polarisation occurs because the service sector is more polarised in occupational and income terms than the manufacturing sector that it replaces. However, the results of many studies suggest that deindustrialisation has not resulted in social polarisation. Instead, deindustrialisation has produced a professionalised occupational structure alongside high levels of unemployment. The results of this study of the Johannesburg region confirm that deindustrialisation results in professionalisation rather than polarisation. We then proceed to examine this outcome by analysing the statistical relationship between economic restructuring and the changing occupational structure. Our results suggest that changes in the overall occupational structure were caused by changes within each economic sector rather than by the growth of service sector employment and the decline of manufacturing sector employment.