Anomalies in net present value calculations?

In a recent issue of Economics Letters (67 (2000) 349¯351), Oehmke notes that 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 increase as the discount rate increases, or to decrease as the discount rate decreases. Oehmke characterizes this behavior as an anomaly which `may make the net present value unsuitable for certain types of projectselection decisions.ʹ 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 and the discount rate and only the interval of plausible discount rates is known