A practical matter, many managers seem to understand already that there is something wrong with the simple NPV rule as it is taught—that there is a value to waiting for more information and that this value is not reflected in the standard calculation. In fact, managers often require that an NPV be more than merely positive. In many cases, they insist that it be positive even when it is calculated using a discount rate that is much higher than their company’s cost of capital. Some people have argued that when managers insist on extremely high rates of return they are being myopic. But we think there is another explanation. It may be that managers understand a company’s options are valuable and that it is often desirable to keep those options open