Bài giảng Tiếng Anh về Risk Analysis (phân tích rủi ro)
Trang 1SECTION RISK ANALYSIS
Trang 2RISK ANALYSIS
Risk introduction
Risk analysis tools
Risk reducing solutions
Trang 4WHAT IS RISK?
Risk, in traditional terms, is viewed as a
‘negative’ Webster’s dictionary, for instance,
defines risk as “exposing to danger or hazard” The Chinese symbols for risk, reproduced below, give a much better description of risk
The first symbol is the symbol for “danger”,
while the second is the symbol for
“opportunity”, making risk a mix of danger and opportunity
Trang 5WHAT IS RISK?
Risk is possibility of difference between actual outcome and expected outcome as planned
Trang 6WHY RISK ANALYSIS ?
Future Certainty is Uncertainty
Trang 7Project returns are spread over time
Most variables affecting NPV are subject to high level of uncertainty
Information and data needed for more accurate forecasts are costly to acquire
Need to reduce the likelihood to undertake a "bad" project while not failing to accept a "good" project
WHY RISK ANALYSIS ?
Trang 8Business is associated with uncertainty
To deal with uncertainty:
to adapt to possible change
Predict and limit uncertain elements
WHY RISK ANALYSIS ?
Trang 9Decision making contexts
Trang 11Business risk Financial risk Strategic risk
TYPES OF RISK
Trang 14STRATEGIC RISK
Strategic risk relating fundamental changes in the economic and political environment
TYPES OF RISK
Trang 15RISK ANALYSIS TOOLS
Sensitivity Analysis
Scenarios Analysis
Monte Carlo Risk Analysis
Software: Crystal-Ball, @Risk
Trang 16Sensitivity Analysis is the first step to risk analysis
Test the sensitivity of a project's outcome (NPV) to changes in one parameter value at a time
Basically "What if" analysis
Allows you to test which variables are important as a source of risk
A variable is important depending on:
Its share of total benefits or costs
Likely range of values
SENSITIVITY ANALYSIS
Trang 17LIMITATIONS OF SENSITIVITY ANALYSIS
Range and probability distribution of variables
Sensitivity analysis doesn't focus on the realistic range
of values Sensitivity analysis doesn't represent the probabilities for each range Generally high probability of values close to mean and a small probability of being at the extremes.
Direction of effects
For most variables, the direction is obvious A) Revenue increases NPV increases B) Cost increases NPV decreases C) Inflation Not so obvious
Continue next page
Trang 18One-at-a-time testing is not realistic because of correlation among variables
A) If Quantity (Q) sold increases, costs will increase
Profits = Q (P - UC)
B) If inflation rate changes, all prices change C) If exchange rate changes, all tradable goods' prices and foreign liabilities change.
One method of dealing with these combined or
correlated effects is scenario analysis
LIMITATIONS OF SENSITIVITY ANALYSIS
Trang 19SCENARIO ANALYSIS
Scenario analysis recognizes that certain
variables are interrelated Thus a small number
of variables can be altered in a consistent
manner at the same time.
What is the set of circumstances that are likely
to combine to produce different "cases" or
"scenarios"?
A Worst case / Pessimistic case
B Expected case / Best estimate case
C Best case / Optimistic case
Note: Scenario analysis does not take into account the Probability of cases arising
Trang 20SCENARIO ANALYSIS
Interpretation is easy when results are
robust:
A Accept project if NPV > 0 even in the worst case
B Reject project if NPV < 0 even in the best case
C If NPV is sometimes positive, sometimes negative, then results are not conclusive Unfortunately, this would be the most common case.
Trang 21MONTE CARLO METHOD OF RISK ANALYSIS
A natural extension of sensitivity and scenario analysisSimultaneously takes into account different probability distributions and different ranges of possible values for key project variables
Allows for correlation (co-variation) between variablesGenerates a probability distribution of project
outcomes (Cash flows, NPV) instead of just a single
Trang 22STEPS IN BUILDING
A MONTE CARLO SIMULATION
1 Mathematical model: project evaluation spreadsheet
2 Identify variables which are sensitive and uncertain
3 Define uncertainty
Establish a range of options (minimum and maximum)
Allocate probability distribution, most common distributions being: Normal distribution, Triangular distribution, Uniform distribution, Step distribution
4 Identify and define correlated variables
Positive or negative correlation
Strength of correlation
5 Simulation model: does a series of analysis for various
combinations of parameter values
6 Analysis of results
Statistics
Distributions
Trang 23F3 F4 V6
V1 V2
V3 V4 V5
Trang 24FORECASTING THE OUTCOME OF
x x x
Maximum
Minimum Observations
Minimum Maximum
Variable Value Probability
0.1
Minimum Maximum
Variable Value
0.3 0.5
0.1
Time
Now
Trang 25The Single -Value Estimate
Variable Value Probability
x x
x
x x
x
x xx
The Deterministic Probability Distribution
1.0
FORECASTING THE OUTCOME OF
A FUTURE EVENT
Trang 26DETERMINISTIC VS SIMULATION ANALYSIS
$
Simulation Analysis
Price Quantity
Revenue (V1 x V2) Materials
Salaries Expenses Operating Cost (V3+V4+V5) Fixed Cost
Total Costs (F2 + V6)
Profit/Loss (F1 - F3)
V1 V2 F1 V3 V4 V5 F2
F3 F4 V6
Trang 27FOUNDATIONS OF RISK ANALYSIS PROBABILITY DISTRIBUTIONS
Trang 28FOUNDATIONS OF RISK ANALYSIS PROBABILITY DISTRIBUTIONS
Non-Standard Flexible Distributions
Trang 30SIMULATION RUNS USING COMPUTER PACKAGE
$
Results
Price Quantity Revenue (V1 x V2)
Materials Salaries Expenses Operating Cost (V3+V4+V5)
Fixed Cost
Total Costs (F2 + V6)
Profit/Loss (F1 - F3)
V1 V2 F1 V3 V4 V5 F2
F3 F4
y
y x
R1 R2 R3 R4
V6
Trang 31Deterministic Analysis Simulation Analysis
Trang 33CASE 1: PROBABILITY FOR NEGATIVE N.P.V = 0
Probability Cumulative Probability
-Decision: Accept
+
Note: Lower end of cumulative probability distribution is to the
right of zero N.P.V point
Trang 34CASE 2: PROBABILITY FOR POSITIVE N.P.V = 0
Probability Cumulative Probability
-Decision: Reject
+
Note: Higher end of cumulative probability distribution is to
the left of zero N.P.V point
Trang 35CASE 3: THE PROBABILITY FOR ZERO N.P.V IS GREATER THAN 0 BUT LESS THAN 1
Probability Cumulative Probability
Trang 36CASE 4: MUTUALLY EXCLUSIVE PROJECTS
GIVEN THE SAME PROBABILITY, ONE PROJECT ALWAYS SHOWS A HIGHER RETURN
Probability Cumulative Probability
Trang 37Case 5: Mutually Exclusive Projects - High Return versus Low Loss
Probability Cumulative Probability
Need to know attitude toward risk:
A If risk neutral, then uncertain which is best.
B If risk averse, then B preferred to A.
C If risk lover, then A may be preferred to B.
Trang 38SIMPLE EXAMPLE
PROJECT: OIL SPECULATION
Buy a barrel of oil today and sell it in a year's time
Steps:
1) What is the RANGE of possible values?
Minimum value: Zero probability of being below $10
Maximum value: Zero probability of being higher than $60
2) What is the PROBABILITY of finding values
between these extremes?
Trang 39RELATIVE PROBABILITY DISTRIBUTION FOR PRICE OF OIL NEXT YEAR
Price of Oil ($/barrel)
10 15 20 25 30 40 50 60
Trang 40SINGLE - VALUED OR DETERMINISTIC MODEL
Based on BEST estimate or expected values
= $27.75 NPV = -20 + 27.75/1.1 = 5.23
Result: Therefore, undertake the project
Trang 41MONTE CARLO SIMULATION OF MODEL
Repeatedly (500 times, for example) pick price values from
distribution at random This is done by picking a random
number between 0 and 100% and looking up the corresponding price value from the cumulative probability distribution For each simulation, calculate value of NPV After 500 simulation runs,
500 values of NPV are obtained for which expected NPV and
other characteristics of NPV distribution can be found.
Trang 42OIL SPECULATION PROJECT: BASE CASE
Assumptions: -P0 = $20
-r = 0.10 Step Rectangular Distribution
Range for Next year’s Oil Price $10 to $60
Trang 43Assumptions: -P0 = $20
-r = 0.10
• Step Rectangular Distribution
• Range for Next Year’s Oil Price $10 to $60
•500 Model Runs
-15 -10 -5 0 5 10 15 20 25 30 35 Expected Value (NPV) = 5.29 Standard Deviation = 9.24
Trang 44Let next year’s oil price range be as follows:
Trang 45Base Case with Uniform Distribution
100% Probability of result falling below corresponding value
Trang 46Cumulative NPV Distribution
Base Case with Normal Distribution
100% Probability of result falling below corresponding value
Trang 47Normal Distribution with Range ($10, $45.50)
100% Probability of result falling below corresponding
Trang 48SUMMARY OF RESULTS FOR OIL SPECULATION PROJECT
A Base Case
B Base Case with Narrower Oil Price
Range ($10 to $30)
C Base Case with Uniform Distribution
D Base Case with Normal Distribution
E Base Case with Normal Distribution
Trang 49HOW TO REDUCE THE COST OF RISK
Use Capital and Futures Markets
Use forward, futures, and option markets to hedge specific project risks
Use the capital market to diversify the risk to equity
owners; ideally, diversification will eliminate unique or unsystematic risk and reduce the cost of equity capital
If there is no well-developed capital market then risks can
be reduced by spreading them over more investors
Use Contractual Arrangements to Reallocate Risks
and Returns
Risk Shifting
Risk Management
Trang 50CONTRACTING CRITERIA
Contract with lowest cost (highest return if
investment occurs) not necessarily best contract
Efficient contracts may provide:
better risk shifting - better distribution of cost across
Trang 51ZERO SUM VERSUS POSITIVE SUM PERSPECTIVES
Cost focus is implicitly a zero sum perspective
What one party gains the other loses
Efficiency perspective is explicitly a positive sum
perspective With right contract one party can gain substantially without corresponding cost to other party
Trang 52RISK SHIFTING
The following options are available:
Contracts that limit the range of values of a particular cash flow item,
or of net cash flow.
For example, a buyer may agree to purchase a minimum quantity
or to pay a minimum price in order to be sure of delivery; these
measures would put a lower bound on the sales revenue.
Similar measures would include:
a limited product price range
•a fixed price growth path
•an undertaking to pay a long-run average price
•specific price escalator clauses that would maintain the
competitiveness of the product, e.g indexing price to the price of a close substitute
Trang 53Re: Quickfix Project
contract that specifies that unit costs (co)
will not rise above $12
0.1 0.3 0.5 0.7 0.9
Expected value of NPV = - $0.74 Srd Deviation = $44.41
Expected loss from accepting = 18.28 Expected loss from rejecting = 17.54
Trang 54Risk-sharing contracts that reduce the risk borne by investors by increasing the correlation between sales revenue and some cost items
e.g., - profit sharing contract with labor
bonds with interest rates indexed to the product’s sales price
Risk-sharing contracts that decrease the correlation between benefit items or alternatively between cost items
CONTRACT THAT RESTRUCTURE INTRA-PROJECT CORRELATIONS
Trang 55- The benefits from restructuring correlations are based on the formula
for the variance of the sum of two random variables (x and y)
For example, let:
x = revenues (R)
y = costs (C)
a = 1, b = -1v(net profit) = v(R-C) = v(R) + V(C) - 2 cov(R,C)
- any measure that will increase the positive correlation between R and C will increase cov (R,C) and reduce the variance of the net profit
CONTRACT THAT RESTRUCTURE INTRA-PROJECT CORRELATIONS
Trang 560.1 0.3 0.5 0.7 0.9
Re: Quickfix Project
- contract with supplier that establishes a cost ceiling of $12
- correlated initial selling price (po) and unit cost (Co) such that 18<Po<20 and correlation between Co & Po = +0.6
Trang 570.1 0.3 0.5 0.7 0.9
Re: Quickfix Project
- cost ceiling of $12 -contract for selling price linked to initial costs (Co)
If Co < 9, Po = 16; otherwise Po = 20
P(NPV<0) = 3%
Trang 580.1 0.3 0.5 0.7 0.9
Re: Quickfix Project
- cost ceiling of $12 -Revised contract for selling price
If Co < 9, Po = $16
9 < Co < 11, Po = $19; otherwise Po = $20
Trang 590.1 0.3 0.5 0.7 0.9
Re: Quickfix Project
- cost ceiling of $12 -Revised contract for selling price
If Co < 9, Po = $16.50
9 < Co < 11, Po = $18.50; otherwise Po = $19.50
Trang 60Similarly, adding another product line will decrease the
variance of revenues provided that the revenues form the new
V(R o + R n ) = V(R o ) + V(R n ) + 2cov(R o , R n )
Also, any measure that reduces the positive correlation of costs will reduce the variance of total cost, which should also have the effect of reducing the variance of net profit
RESTRUCTURE INTRA-PROJECT CORRELATIONS
Trang 61DIVERSIFICATION REDUCES RISK
Example A:
An island economy trying to develop its tourist industry
The chief source of uncertainty is the weather
Rate of return from manufacturing activities Weather Probability Suntan Lotion Umbrellas
Trang 62Portfolio consisting of 50% suntan lotion shares and 50% umbrella shares
Note that in this case the Partial correlation
coefficient = -1
DIVERSIFICATION REDUCES RISK
Trang 63RISK POOLING REDUCES RISK
Let yi = possible returns from a risky project
Assume that there are many such projects and that their returns are independently and identically distributed.
Without Pooling (i.e investing in only one project)
Expected Value: E(yi) = y (mean return)
Variance: V(yi) = V(y)
With Pooling (e.g buying shares in a number (n) if similar
projects) Let ai = proportion of total investment in each project = 1/n
Expected Value: aiE[y1+y2+ +yn]=ny/n=y
Variance: V[ai(y1+y2+ +yn)]
= V[y1/n+y2/n+ +yn/n]
= nV[y/n] = nV[y]/n 2 = V[y]/n lim V[y]/n = 0
Trang 64EXAMPLE OF OIL EXPLORATION
Assume there are 100 firms in the oil exploration business
Each has $1 million invested and each drills one
well, which is independent of the others
Outcomes Probability Profit Rates of Return
Trang 65If an investor puts all his/her money in the shares of one company, then the risk would be very high
However, if an investor constructs a portfolio
consisting of one share of each of the 100 companies, the riskiness of this portfolio will equal:
V[R] = 1.44 [R] / n = 12%
Question: Which risk should be included in the rate
of return that determines a project’s value (NPV)?
EXAMPLE OF OIL EXPLORATION
Trang 66RISK MANAGEMENT
Problem:
Many projects have
large investment outlays
long periods of project payout
incomplete sharing of information and technology especially with foreign investors
differences in the ability of the parties to bear risks
unstable contracts
Projects may be attractive in aggregate but are
unattractive to one or more parties due to uncertainties about sharing risks and returns
The result is that attractive projects are not being undertaken
Trang 67CONTRACTING RISKS
Potential unilateral departures from contract terms
by one party that jeopardizes the other party’s
position
Examples
Downside Risks
Contractor walks away from project
Government defaults on agreement if the share (of a smaller pie) going to the contractor is perceived to be too large
Trang 68TAKING ACCOUNT OF CONTRACTING RISKS
IN ESTIMATING EXPECTED CASH FLOWS
Effect of contracting risk on total contractor returns.
- The contractor may not be permitted to share in the upside returns
- Hence, the contractor should evaluate the project using a “realistic”
probability distribution that reflects any contracting risks.