CMA Final · Strategic Financial Management
Evaluation of Risky Proposals for Investment Decisions: formula sheet
Key formulas
- Expected value of cash flow
- E(CF) = Σ (Pᵢ × CFᵢ)
- Pᵢ is the probability of outcome i. The probabilities must add up to 1.
- Standard deviation of cash flow
- σ = √[ Σ Pᵢ × (CFᵢ − E(CF))² ]
- Measures spread around the expected value. A higher σ means higher stand-alone risk for the same mean.
- Coefficient of variation
- CV = σ ÷ Expected value
- Risk per rupee of expected return. Use it to compare projects of different size or different means.
- Risk-adjusted discount rate
- RADR = Risk-free rate + Risk premium
- A riskier project gets a higher rate. Covered in detail in its own topic.
- Certainty equivalent coefficient
- α = Certain cash flow ÷ Risky expected cash flow
- α lies between 0 and 1 for a risk-averse decision maker. Multiply expected cash flows by α, then discount at the risk-free rate.
- Risk-adjusted discount rate
- RADR (k) = Rf + risk premium
- Under CAPM the premium is β × (Rm − Rf). Questions may give the premium directly or ask you to build it.
- NPV using RADR
- NPV = Σ [E(CFt) ÷ (1 + k)^t] − Initial outlay
- Use expected (uncorrected) cash flows. Do not also scale them by coefficients.
- CE coefficient
- α(t) = Certain cash flow ÷ Expected risky cash flow
- Lies between 0 and 1 for a risk-averse decision-maker. Lower means more risk.
- NPV using certainty equivalent
- NPV = Σ [α(t) × E(CFt) ÷ (1 + Rf)^t] − Initial outlay
- Discount at the risk-free rate only. The initial outlay is usually certain, so its coefficient is 1 unless stated.
- Equivalence of the two methods
- α(t) = [(1 + Rf) ÷ (1 + k)]^t
- Holds when both methods give the same present value and k is constant. Useful to find an implied coefficient.
- NPV
- NPV = Σ [CFt ÷ (1 + k)^t] − Initial investment
- Base-case NPV is the starting point for every sensitivity or scenario question.
- Break-even annual cash flow (level inflows)
- Break-even cash flow = Initial investment ÷ Annuity factor (k, n)
- Valid when inflows are equal each year and there is no salvage value. Otherwise equate PV of inflows to the outflow.
- Sensitivity of NPV to cash inflows
- % fall in inflows that makes NPV zero = NPV ÷ PV of inflows × 100
- Applies when the whole inflow stream changes by the same percentage.
- Sensitivity of NPV to initial investment
- % rise in investment that makes NPV zero = NPV ÷ PV of investment × 100
- Use PV of the outflow; if the investment is all at time 0, this is the investment itself.
- Scenario NPV and expected NPV
- Expected NPV = Σ (Probability of scenario × NPV of scenario)
- Probabilities must add to 1. Use only if probabilities are given.
- Range of NPV
- Range = Best-case NPV − Worst-case NPV
- A simple measure of how widely the outcome can vary.
- Expected value
- E(X) = Σ pᵢ × Xᵢ
- Probabilities must sum to 1. Applies to cash flows or to NPVs.
- Expected NPV
- ENPV = Σ [E(CFₜ) ÷ (1 + r)ᵗ] − Initial outlay
- Initial outlay is treated as certain unless the question gives its distribution.
- Standard deviation of a distribution
- σ = √[Σ pᵢ × (Xᵢ − E(X))²]
- Use deviations from the mean, weighted by probability.
- σ of NPV, independent yearly cash flows
- σ(NPV) = √[Σ σₜ² ÷ (1 + r)²ᵗ]
- Square the discount factor. Add variances, then take the root.
- σ of NPV, perfectly correlated cash flows
- σ(NPV) = Σ [σₜ ÷ (1 + r)ᵗ]
- Add the discounted standard deviations. This gives the highest σ.
- Coefficient of variation
- CV = σ ÷ ENPV
- Lower CV means lower risk per rupee of expected NPV. Meaningful when ENPV is positive.
- Z value for probability under normal distribution
- Z = (X − ENPV) ÷ σ
- For P(NPV < 0), use X = 0. Read the area from the normal table.
- Expected value at a chance node
- EV = Σ (probability × value of branch)
- Probabilities on the branches leaving the node must sum to 1. Use PV of the branch values at the same date.
- Value at a decision node
- Value = highest of (value of each alternative after its own outlay or proceeds)
- Choose the maximum for NPV or profit. Cross out (prune) the rejected branches.
- Present value of a later value
- PV = Value at time t ÷ (1 + r)^t
- Discount the rolled-back value to time 0 before deducting the initial outlay.
- Expected NPV of a strategy
- Expected NPV = PV of expected inflows (with best later decisions) − initial outlay
- Accept if it is positive. Between mutually exclusive strategies, pick the higher expected NPV.
- Joint probability of a path
- P(path) = product of the branch probabilities along the path
- Use it when the question asks for the probability of a particular outcome or for NPV along each path.
- Expanded (strategic) NPV
- Expanded NPV = Base NPV (without option) + Value of real option
- Accept the project if expanded NPV is positive, even when base NPV is negative.
- Expected NPV from simulation
- Mean NPV = Σ NPVi ÷ n
- n is the number of trials. Also report standard deviation and P(NPV < 0).
- Abandonment decision
- Abandon if salvage value > PV of continuing cash flows
- Compare at the decision date using the same discount rate.
- Value of abandonment option
- Option value = Σ Probability × max(Salvage value − PV of continuing, 0)
- Applies to each outcome at the decision date, then discount to today.
- Expansion option payoff
- Payoff = max(PV of expansion inflows − Expansion outlay, 0)
- Exercise only when the payoff is positive.
- Option analogy
- Underlying = PV of project inflows; Exercise price = investment outlay; Time = decision window; Volatility = uncertainty of inflows
- Use when Black-Scholes is asked for a real option. Higher volatility and longer time raise option value.
- Expected NPV
- ENPV = Σ Pi × NPVi
- Pi is the probability of each outcome. Probabilities must add up to 1.
- Standard deviation of a project
- σ = √[Σ Pi × (NPVi − ENPV)²]
- Measures total risk of one project, in rupees.
- Coefficient of variation
- CV = σ ÷ ENPV
- Risk per rupee of expected NPV. Lower is better. Use it only when ENPV is positive.
- Portfolio expected NPV
- ENPVp = w1 × ENPV1 + w2 × ENPV2
- If both projects are taken in full, weights are 1 and ENPVp is the plain sum.
- Portfolio SD of two projects
- σp = √(w1²σ1² + w2²σ2² + 2 × w1 × w2 × ρ12 × σ1 × σ2)
- With both projects in full (w = 1): σp = √(σ1² + σ2² + 2ρ12σ1σ2).
- Covariance
- Cov12 = ρ12 × σ1 × σ2
- If covariance is given, use it in place of ρσ1σ2.
- Limiting cases of correlation
- ρ = +1: σp = σ1 + σ2 | ρ = 0: σp = √(σ1² + σ2²) | ρ = −1: σp = |σ1 − σ2|
- The last holds for two projects taken in full. ρ always lies between −1 and +1.
Quick revision
- Risk means outcomes with known or estimable probabilities; uncertainty means probabilities cannot be reliably assigned.
- Risk-adjusted discount rate raises the rate for riskier projects; it adjusts the denominator.
- Certainty equivalent converts uncertain cash flows to certain ones; it adjusts the numerator.
- Certainty equivalent factor = certain cash flow ÷ expected risky cash flow; it lies between 0 and 1 for a risk-averse decision maker.
- Sensitivity analysis changes one variable at a time and observes the effect on NPV.
- Scenario analysis changes several variables together, such as best, expected and worst cases.
- Expected NPV = Σ (probability × NPV of each outcome).
- Standard deviation = √Σ p × (x − mean)²; it measures absolute risk.
- Coefficient of variation = standard deviation ÷ expected NPV; use it to compare projects of different size.
- Decision trees are solved backward, from the final outcomes to the first decision.
- Monte Carlo simulation draws random values from assumed distributions to build a distribution of NPV.
- Real options value the flexibility to expand, delay, abandon or switch a project.
Common mistakes
- Using risk and uncertainty as exact synonyms in a question that asks for the difference. Fix: When asked for the difference, write that risk has known or estimable probabilities and uncertainty does not. Add one example for each.
- Choosing the project with the higher expected NPV without looking at spread. Fix: Always compute σ or CV when probabilities are given and comment on both return and risk before concluding.
- Discounting certainty equivalent cash flows at the RADR instead of the risk-free rate. Fix: CE already removes the risk from the cash flow. Discount at the risk-free rate only. Using the RADR would count risk twice.
- Applying the CE coefficient to the initial outlay when it was not given. Fix: Treat the outlay as certain (coefficient 1) unless the question gives a coefficient for year 0.
- Changing several variables at once and calling it sensitivity analysis. Fix: In sensitivity analysis change one variable and hold the rest at base values. Changing a combined set of inputs is scenario analysis.
- Dividing the NPV by the wrong base, for example by the annual cash flow instead of the PV of inflows. Fix: Use NPV ÷ PV of inflows for cash-flow sensitivity and NPV ÷ PV of the investment for investment sensitivity.
- Adding yearly standard deviations without discounting them Fix: Discount σₜ by (1 + r)ᵗ for correlated flows, or discount σₜ² by (1 + r)²ᵗ for independent flows.
- Discounting σ² with (1 + r)ᵗ instead of (1 + r)²ᵗ Fix: Square the discount factor whenever you discount a variance. Take the root only at the end.
- Working left to right and choosing the best branch at the first decision without looking ahead. Fix: Always roll back from the right. A first-stage choice is judged by the best value of everything after it.
- Forgetting to deduct the outlay on an alternative before comparing it with others at a decision node. Fix: At each decision node, write net value = expected inflows − outlay for every alternative, then compare.
Exam tips
- In theory questions, write the difference between risk and uncertainty in two clear lines and add one example each. This scores quickly.
- In case-based MCQs, match the stated event to its source: a rival price cut is competitive risk, a rate hike is market risk, rupee movement on an overseas project is international risk.
- In numerical questions, show expected value, σ and CV in a table. Step marks are given even if one figure goes wrong.
- Always end with a recommendation that mentions both return and risk. A bare number is not a decision.
- Read whether the question asks for stand-alone, corporate or market risk. The answer changes with the view.
- Check the wording to find the method. Premium or higher rate means RADR; coefficient or sure amount means CE. Do not mix them in one calculation.
- Write the discount rate in the first line of your answer. Marks are often given for the correct rate.
- The MCQs test concepts: which rate is used in CE, what a lower coefficient means, and which method assumes risk rises each year. Revise these in one line each.