Testing for a Unit Root in the Net Discount Rate: A Survey of the Empirical Results

Abstract

This study provides a survey of the empirical results associated with testing for a unit root in the net discount rate. As suggested by the literature, the use of the historical average of the net discount rate in the calculation of the present value of lost future earnings is valid if the net discount rate follows a mean reverting, stationary process. However, if the net discount rate follows a mean averting, non-stationary process forensic economists should perhaps use the current value of the net discount rate in such calculations. A majority of the studies surveyed indicate that the net discount rate experienced a structural break in the late 1970s-early 1980s. In general, if the net discount rate is stationary as a result of a structural break, forensic economists should use the average net discount rate over the post-break period.