III. Practical Problems in
10. A Project is Not a Black
only 1 or 2 may ever get to market. The 1 or 2 that are marketed have to
generate enough cash flow to make up for the 9,999 or 9,998 that fail.)
2. Market success. FDA approval does not guarantee that a drug will sell. A
competitor may be there first with a similar (or better) drug. The company
may or may not be able to sell the drug worldwide. Selling prices and
marketing costs are unknown.
Imagine that you are standing at the top left of Figure 10.5. A proposed research
program will investigate a promising class of compounds. Could you write down
the expected cash inflows and outflows of the program up to 25 or 30 years in the
future? We suggest that no mortal could do so without a model to help; simulation
may provide the answer.
13
Simulation may sound like a panacea for the world’s ills, but, as usual, you pay
for what you get. Sometimes you pay for more than you get. It is not just a matter
of the time and money spent in building the model. It is extremely difficult to esti-
mate interrelationships between variables and the underlying probability distri-
butions, even when you are trying to be honest.
14
But in capital budgeting, fore-
casters are seldom completely impartial and the probability distributions on which
simulations are based can be highly biased.
In practice, a simulation that attempts to be realistic will also be complex. There-
fore the decision maker may delegate the task of constructing the model to man-
agement scientists or consultants. The danger here is that, even if the builders un-
derstand their creation, the decision maker cannot and therefore does not rely on
it. This is a common but ironic experience: The model that was intended to open
up black boxes ends up creating another one.
268 PART III
Practical Problems in Capital Budgeting
13
N. A. Nichols, “Scientific Management at Merck: An Interview with CFO Judy Lewent,” Harvard Busi-
ness Review 72 (January–February 1994), p. 91.
14
These difficulties are less severe for the pharmaceutical industry than for most other industries.
Pharmaceutical companies have accumulated a great deal of information on the probabilities of scien-
tific and clinical success and on the time and money required for clinical testing and FDA approval.
15
Some simulation models do recognize the possibility of changing policy. For example, when a phar-
maceutical company uses simulation to analyze its R&D decisions, it allows for the possibility that the
company can abandon the development at each phase.
10.3 REAL OPTIONS AND DECISION TREES
If financial managers treat projects as black boxes, they may be tempted to think only
of the first accept–reject decision and to ignore the subsequent investment decisions
that may be tied to it. But if subsequent investment decisions depend on those made
today, then today’s decision may depend on what you plan to do tomorrow.
When you use discounted cash flow (DCF) to value a project, you implicitly as-
sume that the firm will hold the assets passively. But managers are not paid to be
dummies. After they have invested in a new project, they do not simply sit back and
watch the future unfold. If things go well, the project may be expanded; if they go
badly, the project may be cut back or abandoned altogether. Projects that can easily
be modified in these ways are more valuable than those that don’t provide such flex-
ibility. The more uncertain the outlook, the more valuable this flexibility becomes.
That sounds obvious, but notice that sensitivity analysis and Monte Carlo
simulation do not recognize the opportunity to modify projects.
15
For example,