On the Risk of Stocks in the Long Run: A Note
指出Zvi Bodie关于长期持有股票风险随时间增加的证明依赖于一个不恰当的假设，即股票标准差在所有持有期恒定，从而质疑其结论。
In a recent article in this journal, Zvi Bodie used a simplified Black–Scholes model to prove that the cost of insuring a long-term stock portfolio against earning less than the risk-free rate increases over time. Bodie believes that this means the risk of investing in common stocks increases over time and that the conventional wisdom of the investment community concerning time diversification is a fallacy. Bodie's proof relies on a constant standard deviation for common stock over all holding periods. This assumption, however, may not be appropriate for long-term stock portfolios. This article is not available online.