A number of new political rights and property rights measures are used to explore the link between institutions and economic activity for South Africa over the 1935-97 period. The study uses cointegration analysis to establish the importance of property rights and political instability both as determinants of the level of the desired per capita capital stock, and of investment expenditure. Political freedoms are established as an outcome variable, in a perverse modernization link with per capita output. Some conclusions on the nature of the investment function for South Africa also follow. The financial support of the South African Network of Economic Research is gratefully acknowledged. Responsibility for views expressed remains ours alone.