Anomalies in net present value calculations?

In a recent issue of Economics Letters (67 (2000) 349-351), Oehmke notes th at in exactly the cases that may give rise to either none or more than one internal rate of returns, it is possible for the net present value to incre ase as the discount rate increases, or to decrease as the discount rate dec reases. Oehmke characterizes this behavior as an anomaly which 'may make th e net present value unsuitable for certain types of project-selection decis ions.' This note shows how the NPV criterion can be applied in a specified subset of cases where there is no monotonic relationship between the NPV an d the discount rate and only the interval of plausible discount rates is kn own. (C) 2001 Elsevier Science B.V. All rights reserved.