Unfortunately, some sharp readers have called to their attention a 14.3 percent error. They claimed to have a higher average rate of return for 1984-1993 than the Dow Jones average. That figure is now disputed. I enjoyed the reason for why the data produced some discrepancies. A error in computer input occurred.
People enter data.
The publishers, Hyperion, of their investment books hired Price Waterhouse to find the discrepancy. Also, the publisher printed and placed correction slips inside the ladies' investment books. One of my students suggested the ladies still made the money. That is missing the point. You want integrity at all times in the writing, whether investment advice, or whatever.