NOT DOING BUSINESS WITH SOUTH AFRICA

Some churches and other institutional investors don't want to invest in any corporation or bank with an involvement in South Africa. But it can cost them money. The Boston Company has offered a portfolio of ``South Africa-Free'' stocks for about two years. It includes some 82 percent of the stocks included in Standard & Poor's 500 Index.

However, an index developed by the Boston Company to measure the effects of divestiture of South African-related stocks and the relative performance of South Africa-free portfolios shows that since the end of 1983, the S&P 500 would have provided an annualized return of 16.52 percent, versus 14.98 percent for the Boston Company's South Africa-Free Equity index.

In other words, an antiapartheid stance has reduced performance by 1.54 percent a year.