One example would be excess capacity on a machine or a computer. Most firms cannot
lease or sell excess capacity, but using that capacity now for a new product may cause the
businesses to run out of capacity much earlier than otherwise, leading to one of two costs:
• They assume that excess capacity is free, since it is not being used currently and
cannot be sold off or rented, in most cases.
• They allocate a portion of the book value of the plant or resource to the project.
Thus, if the plant has a book value of $ 100 million and the new project uses 40%
of it, $ 40 million will be allocated to the project.
We will argue that neither of these approaches considers the opportunity cost of using
excess capacity, since the opportunity cost comes usually comes from costs that the firm
will face in the future as a consequence of using up excess capacity today. By using up
excess capacity on a new project, the firm will run out of capacity sooner than it would if
it did not take the project. When it does run out of capacity, it has to take one of two
paths:
• New capacity will have to be bought or built when capacity runs out, in which
case the opportunity cost will be the higher cost in present value terms of doing
this earlier rather than later.
• Production will have to be cut back on one of the product lines, leading to a loss
in cash flows that would have been generated by the lost sales.
Again, this choice is not random, since the logical action to take is the one that leads to
the lower cost, in present value terms, for the firm. Thus, if it cheaper to lose sales rather
than build new capacity, the opportunity cost for the project being considered should be
based on the lost sales.
A general framework for pricing excess capacity for purposes of investment
analysis asks three questions:
(1) If the new project is not taken, when will the firm run out of capacity on the
equipment or space that is being evaluated?
(2) If the new project is taken, when will the firm run out of capacity on the equipment or
space that is being evaluated? Presumably, with the new project using up some of the
excess capacity, the firm will run out of capacity sooner than it would have otherwise.
(3) What will the firm do when it does run out of capacity? The firm has two choices: