Implicit Inflation and Interest Rates in Discounting Personal Injury Economic Losses. Comment
评论了Jones关于人身伤害经济损失折现的方法，指出其虽然批评他人使用通胀预测，但自身在折现公式中隐含了对未来利率的预测，并讨论了再投资利率的不确定性。
In a recent article [41 in this Journal David D. Jones presents what he considers to be the appropriate to the problem of calculating the present value of economic loss due to personal injury and wrongful death. He criticizes the real discount rate or its variant the total offset approach as incorporating forecasts [4, p. 149] of inflation in the calculation of the present value of future economic loss. It is the purpose of this article to demonstrate that the alternative that Jones proposes does exactly the same thing that he rails against in that he also incorporates forecasts in the discounting formula. However, his involves a hidden forecast of future of interest rather than future inflation. In addition other comments will be made on the Jones approach. Jones presents an example whereby the problem is to determine the present value of $ 10,000 of lost wages a year for 30 years. His is to project the wage growth using a 1.5 percent productivity growth factor and a 6.8 percent long-run inflation factor. Future wages are then reduced to present value using a currently available [4,p. 148] 13.6 percent interest rate which yields a present value of the loss of $155,603. Jones argues that the appropriate interest rate in this example is the yield on long-term U.S. Government securities of 20-30 year maturity and that it is possible to lock-in such a yield since is no forecasting problem with interest rates as they are known with certainty. [4,p. 146] What Jones fails to consider or at least inform the reader of is that for coupon bond investments' the interest earned must be reinvested and there is no assurance as to the rate at which it will be reinvested. While the 13.6 percent rate may be locked-in on the original award the reinvested interest will earn whatever the market interest rate is at