Rudd (1979)

Rudd, Andrew. "Divestment of South African Equities: How Risky?" Journal of Portfolio Management, Fall 1979.

From the paper:  "The effect on portfolio risk of excluding the companies operating in South Africa ... is, contrary to intuition, not particularly important."

LK comment:  Strong and important early study treating the problem of South Africa divestment from a multifactor risk management perspective.  See also Rudd (1981).