In order to understand the thought processes such managers may be using, it is useful to step back and examine the NPV rule and how it is used. For anyone analyzing an investment decision using NPV, two basic issues need to be addressed: first, how to determine the expected stream of profits that the proposed project will generate and the expected stream of costs required to implement the project; and, second, how to choose the discount rate for the purpose of calculating net present value. Textbooks don’t have a lot to say about the best way to calculate the profit and cost streams. In practice, managers often seek a consensus projection or use an average of high, medium, and low estimates. But however they determine the expected streams of profits and costs, managers are often unaware of making an implicit faulty assumption. The assumption is that the construction or development will begin at a fixed point in time, usually the present. In effect, the NPV rule assumes a fixed scenario in which a company starts and completes a project, which then generates a cash flow during some expected lifetime—without any contingencies. Most important, the rule anticipates no contingency for delaying the project or abandoning it if market conditions turn sour. Instead, the NPV rule compares investing today with never investing. A more useful comparison, however, would examine a range of possibilities: investing today, or waiting and perhaps investing next year, or waiting longer and perhaps investing in two years, and so on.