"Over the last decade, the South African government has pursued a set of cautious fiscal and monetary policies that have kept inflation and public debt at low levels In spite of these strong fundamentals, the economy has displayed lacklustre growth rates As of 2006, GDP per capita has yet to reach its 1981 level In spite of what could arguably be described as a better fundamental and cyclical basis for accelerated growth,, the country's performance over the past decade has been on par with the rest of sub-Saharan Africa, and considerably below the average growth rate of 3 7 percent in South Asia, and 6 2 percent in East Asia" (Dube, Hausmann and Rodnk 2007 'South Africa identifying the binding constraint on shared growth") Explain what have been the main constraints on growth and employment in South Afnca according to Dube, Hausmann and Rodnk in their article above