
196 Part III Investment risk and return
Self-assessment activity 8.1
Why is risk assessment important in making capital investment decisions?
(Answer in Appendix A at the back of the book)
8.1 INTRODUCTION
The Channel Tunnel is one of many cases where investment decisions turn out to be far
riskier than originally envisaged. The finance director of a major UK manufacturer for
the motor industry remarked, ‘We know that, on average, one in five large capital proj-
ects flops. The problem is: we have no idea beforehand which one!’
Stepping into the unknown – which is what investment decision-making effective-
ly is – means that mistakes will surely occur. Entrepreneurs, on average, have nine
failures for each major success. Similarly, on average, nine empty oil wells are drilled
before a successful oil strike. Sir Richard Branson, head of Virgin Atlantic, once said,
‘the safest way to became a millionaire is to start as a billionaire and invest in the air-
line industry.’
This does not mean that managers can do nothing about project failures. In this and
subsequent chapters, we examine how project risk is assessed and controlled. The var-
ious forms of risk are defined and the main statistical methods for measuring project
risk within single-period and multi-period frameworks are described. A variety of risk
analysis techniques will then be discussed. These fall conveniently into methods intend-
ed to describe risk and methods incorporating project riskiness within the net present
value formula. The chapter concludes by examining the extent to which the methods
discussed are used in business organisations.
■ Defining terms
At the outset, we need to clarify our terms:
■ Certainty. Perfect certainty arises when expectations are single-valued: that is, a par-
ticular outcome will arise rather than a range of outcomes. Is there such a thing as
an investment with certain payoffs? Probably not, but some investments come fair-
ly close. For example, an investment in three-month Treasury Bills will, subject to
the Bank of England keeping its promise, provide a precise return on redemption.
■ Risk and uncertainty. Although used interchangeably in everyday parlance, these
terms are not quite the same. Risk refers to the set of unique consequences for a
given decision that can be assigned probabilities, while uncertainty implies that it
is not fully possible to identify outcomes or to assign probabilities. Perhaps the
worst forms of uncertainty are the ‘unknown unknowns’ – outcomes from events
that we did not even consider.
The most obvious example of risk is the 50 per cent chance of obtaining a ‘head’ from
tossing a coin. For most investment decisions, however, empirical experience is hard to
find. Managers are forced to estimate probabilities where objective statistical evidence is
not available. Nevertheless, a manager with little prior experience of launching a partic-
ular product in a new market can still subjectively assess the risks involved based on the
information he or she has. Because subjective probabilities may be applied to investment
decisions in a manner similar to objective probabilities, the distinction between risk and
uncertainty is not critical in practice, and the two terms are often used interchangeably.
Investment decisions are only as good as the information upon which they rest.
Relevant and useful information is central in projecting the degree of risk surrounding
future economic events and in selecting the best investment option.
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