For owners of a business—and that’s the way we think of shareholders—the academics’ definition of risk is far off the mark, so much so that it produces absurdities. For example, under beta-based theory, a stock that has dropped very sharply compared to the market—as had Washington Post when we bought it in 1973—becomes “riskier” at the lower price than it was at the higher price. Would that description have then made any sense to someone who was offered the entire company at a vastly-reduced price?

