The returns on foreign investment were high. American returns averaged
over 15 percent in 1970-74, declined to 9 percent in I 975, and rose again
to 14 percent in I976-78.78
The South African economy was not autarchic. It was vulnerable in
three respects. First, it required considerable infusions of foreign capital.
Second, except in mining, South Africa did not possess the latest tech-
nology and needed to import heavy machinery and electronic and trans-
portation equipment. Third, South Africa produced no natural oil. Never-
theless, except for brief periods after the disturbances following the
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