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Project risk

Jamal Munshi, Sonoma State Univesity, 1992
All rights reserved

The uncertainty in sales projection causes uncertainties in NCF values and therefore, an uncertainty in the net present value of the project NPV. The degree to which this affects risk depends on two variables: (a) project risk, the standard deviation of the project NPV and (b) correlation, the degree to which the sales projections are correlated with those of the firm as a whole.

If the project is an expansion of the firm's existing business, then the sales are likely to be highly correlated (rifÅ1), i.e., when the firm does poorly, the project is also expected to do poorly and when the firm does well, the project also does well. If the project is a venture into a different kind of business as in diversification, then the project may be only weakly correlated with the firm's business (rifÅ0), i.e., when the firm performs poorly, the project is as likely to do well as poorly since its perfomance is not correlated with that of the firms's.

Equations

  • sp = SUM{(ai2si2+af2sf2+2aiafsif)}
  • mp = aimi+afmf
  • sif= rifsisf
  • where
  • sp = Portfolio risk when i-th project is added to those of the existing firm.
  • mp = Expected value of the portfolio NPV when i-th project is added to those of the existing firm.
  • ai = the fraction of the total NPV of the portfolio contributed by the i-th project.
  • af = the fraction of the total NPV of the portfolio contributed by the existing firm.
  • sif= covariance between the NPV of the i-th project and that of the firm.
  • rif= correlation between the NPV of the i-th project and that of the firm.
  • si = the riskiness of the ith project
  • sf = the riskiness of the existing firm
  • mi = the expected value of the NPV of the ith project
  • mf = the expected value of the NPV of the existing firm
A low correlation gives us an advantage in reducing overall risk of the combination. This is the so called Portfolio Effect.

Evaluation Without Portfolio Effect

When portfolio effects are not taken into consideration, then the riskiness of the project can be evaluated on the basis if its total project risk si. The probability that mi will be negative will correspond to a z-value given by:

zi = mi/si

Evaluation With Portfolio Effect

Consider the firm to be a portfolio of correlated projects. We are now considering adding the i-th project whose correlation to the existing firm's NPV is known. The project is chosen for inclusion into the firm based on the the increase in the overall NPV and riskiness of the firm. The probability that mp will be negative corresponds to the z-value:

zp = mp/sp

Between two mututally exclusive projects A and B, the one with the higher z value will be preferred since it offers a lower probability that the NPV of the combined firm will be negative. Acquisitions of other firms may be treated as projects and evaluated in this manner.

Example Problem:

Three mutually exclusive projects have the characteristics shown below. Our existing assets offer an expected NPV of $203 with a standard deviation of $145. Which project would you choose if risk is not to be taken into account? Ignoring portfolio effects, but taking risk into account, which of the projects is most desirable and why?? If portfolio effects are considered, which should be selected? Why?

  • Project A B C Firm
  • mi 19 32 33 203
  • si 13 21 22 145
  • rif 0.60 1.00 0.72 1.00

Solution if project risk is not considered

Choose the project with the highest NPV. Choose C since 33 gt 32 and 33 gt 19

Solution if correlations are not considered but portfolio effects are ignored

The projects are evaluated on the basis of project risk si as folows:

  • probability that mA will be negative corresponds to zA = 19/13 = 1.4615
  • probability that mB will be negative corresponds to zB = 32/21 = 1.5238
  • probability that mC will be negative corresponds to zC = 33/22 = 1.50
  • Project B offers the lowest probability of negative NPV and is chosen.

Solution if correlations are considered

  • Project A: mp=19+203=222, ai=19/222=8.56% af=203/222=91.44%
  • aii = 0.007325, aff = 0.83615, rif = 0.60
  • sp = Ö(ai2sii+af2sff+2aiafsif) = SQRT{.007325*169 + 0.83615*21025 +
  • 2*.0856*13*.9144*145*0.60} = 133.26
  • zp = 222/133.26 = 1.666
  • Project B: mp=32+203=235, ai=32/222=13.62% af=203/235=86.38%
  • since B and F are perfectly correlated,
  • sp = aisi+afsf = 0.1362*21 + 0.8638*145 = 128.11
  • zp = 235/128.11 = 1.8345
  • Project C: mp=33+203=236, ai=33/236=13.98% af=203/236=86.02%
  • aii=0.01954, aff=0.7399, rif = 0.72
  • sp = Ö(ai2sii+af2sff+2aiafsif) = SQRT{.01954*484 + 0.7399*21025 +
  • 2*.0856*22*.8602*145*0.72} = 126.96
  • zp = 236/126.96 = 1.8588
  • Project C offers the lowest probability of negative NPV and is chosen.