risk management & real options ii. the forecast is always wrong stefan scholtes judge institute...
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Risk Management & Real Options
II. The forecast is always wrong
Stefan ScholtesJudge Institute of Management
University of Cambridge
MPhil Course 2004-05
2 September 2004 © Scholtes 2004 Page 2
NPV – the industry standard
Aim: Value a project that requires an investment now and generates future cash flows over several periods, say several years
Naïve: Value = sum of cash inflows – cash outflows• Treat initial investment as cash outflow in period zero
But: $ 1 today is worth more than $ 1 in a year’s time• Inflation – time value of money• Could invest $1 elsewhere – opportunity cost of capital
Opportunity cost of capital: “Best” rate of return on alternative investment
What does “best” mean? • Bank account 2% p.a.• Government bond 5% p.a.• Stock market 15% p.a.• Venture capital 25% p.a.
2 September 2004 © Scholtes 2004 Page 3
Rewards for risk taking
Three main risks involved in investment
Macro-economic risk (exchange rates, GDP growth, oil price, etc.)• Shared throughout the economy
Default risk• Risk to debt holders: Company defaults
Equity risk• Risk to equity holders: Future cash flows are uncertain
Want reward for taking risk
Taking macro-economic risk is rewarded by government bond rate
Taking default risk is rewarded by corporate spread = corporate debt rate – government bond rate
Equity risk is reflected in company’s “beta” (CAPM Finance textbook)
2 September 2004 © Scholtes 2004 Page 4
Discounted cash flow models
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years in received flowcash of valuesToday'nd
x
d
xnx
n
Value of $1 to be received in the future
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
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0 5 10 15 20 25 30
Time of payment
Pre
sen
t va
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5%
10%
15%
Annual compounding Continuous compounding
2 September 2004 © Scholtes 2004 Page 5
Discounted cash flow models
Discount rate d reflects the annual opportunity cost of capital for a project with a similar “level of risk” (whatever that means…)
• The higher the discount rate, the lower the present value of a future cash outflow (positive cash flow)
• The higher the discount rate, the lower the present value of a future cash inflow (negative cash flow)
Present value (PV) of a project: sum of all discounted future cash flows
Net present value (NPV) = PV minus today’s investment
See Parking Garage.xls for an example of an NPV sheet (without tax considerations)
2 September 2004 © Scholtes 2004 Page 6
How is NPV used?
Is this project economically sensible? • “YES if NPV>0”• Advise changes with discount rate
Which of several projects should we do?• “Choose the ones with larger NPV first, until budget is exhausted”• Ranking changes with discount rate
2 September 2004 © Scholtes 2004 Page 7
What discount rate?
Practice: Discount rate is the return expectation of the capital owners, debtors and equity investors (“weighted average cost of capital”)
BUT:
Cambridge Antibody Technology (or the likes) : “…We know as a relatively young biotech company we should have a discount rate of 20%+. But if we were applying discount rates of this order, we wouldn’t do a single project…”
BP (or the likes): “…We don’t discuss discount rates. We apply a 10% hurdle rate to all our projects…”
Boeing (or the likes): “…Any sensible discount rate would wipe out all our returns beyond a 15 year time horizon – but our aircraft projects have a product life of 30+ years…”
2 September 2004 © Scholtes 2004 Page 8
NPV: Plus and minus
Plus: Setting up an NPV model forces you to think about the logic of
a system’s value generation• What are the key ingredients: costs, revenues• What are the key drivers: demand, prices, unit costs, fixed costs,
etc.• What are the major tax implications: depreciation, etc.
Minus: Which discount rate? Even more important: NPV calculation is based on projections
of uncertain future demand, prices, unit costs, fixed costs, etc., and
THE FORECAST IS ALWAYS WRONG
Secondly, NPV is based on a fixed plan of action• Does not account of deviating from plan if uncertainties unfold
different from expectations (come to this later)
2 September 2004 © Scholtes 2004 Page 9
Cost forecast
0.5 1.0 1.5 2.0 2.5 3.0
15
10
5
Percent of
Occurrences
Median 1.25
Real/Estimated Cost Ratio
Ratio of actual to estimated costs for routine airport resurfacing of runways
Source: R. de Neufville, MIT
2 September 2004 © Scholtes 2004 Page 10
Source: U.S. Department of Energy, 1998Source: U.S. Department of Energy, 1998
121200
101000
8080
6060
4040
2020
0019751975 19801980 19851985 19901990 19951995 20002000 20052005
YearYear
1982
Trend predicted 1981
1984
1985
1986 1987
1991
1995
ActualDo
llars
pe
r B
arr
el
Do
llars
pe
r B
arr
el
Oil price forecast
US DEO oil price forecastsUS DEO oil price forecasts
1983
2 September 2004 © Scholtes 2004 Page 11
Demand forecasts
In the early 1980's McKinsey were hired by AT&T to forecast the growth in the mobile phone market until the end of the millennium.
They projected a global market of 900,000 handsets
Today, 900,000 handsets are sold every three days
2 September 2004 © Scholtes 2004 Page 12
A first cure: Sensitivity analysis
Simplest model: Numbers-in-numbers-out• Need number calculator
Sensitivity analysis = what-if analysis
Improved model: Range-in-range-out• Calculate the range of output values corresponding to a range of
input values of one uncertain variable• Vary one variable at a time
Easily done in a spreadsheet
2 September 2004 © Scholtes 2004 Page 13
Typical graphical output
Sensitivity Chart
-$15,000,000
-$10,000,000
-$5,000,000
$0
$5,000,000
$10,000,000
$15,000,000
$24.00 $29.00 $34.00 $39.00 $44.00
Oil Price
NP
V
2 September 2004 © Scholtes 2004 Page 14
Tornado diagrams
Input ranges typically specified by • Base value (“most likely”)• Pessimistic value • Optimistic value
Base-case: Calculate base value for the output measure (e.g. NPV) on the basis of base values for inputs
Tornado bar: For each input variable• Determine the highest and lowest value of the output measure as
the input variable varies over its rangeR̵ Extremes of output measure typically achieved at either end of the input
range• Determine the range of percentage deviations of the output from its
base value as input varies over its range
Rank the input variables by their impact on percentage deviation of the output variable from the base value
2 September 2004 © Scholtes 2004 Page 15
Tornado Diagram
Tornado Diagram for NPV
-200.0% -150.0% -100.0% -50.0% 0.0% 50.0% 100.0% 150.0% 200.0%
Plant sales
Investment costs
Maintenance
Variable costs
Price
Sales
% Change from Base Value
Illustrates the effect of a RANGE of values of one input variable on the performance measure
E.g.: The “variable cost range” can change the performance measure by more than 100% to either side of its base value
2 September 2004 © Scholtes 2004 Page 16
Problems with sensitivity analysis
Vary uncertainties one-by-one
Varying many inputs simultaneously over their ranges and recording the highest and lowest value of the output measure leads to a huge range of the output measure
• “End-range” scenarios are overly pessimistic or overly optimistic• Difficult to incorporate dependencies of variables (e.g. dependence
of price on demand)
Scenarios are played out for us but we don’t know how likely they are!
Need to enter the world of probability to understand the notion of “likelihood”