Alternative Investment Appraisal Rules
Payback Period
Definition: The number of years required to recover the initial investment through accumulated future cash flows.
Decision Rule: Accept projects that recover their initial outlay within a specified number of years (X-year payback).
Example:
New investment costs £10,000.
Future cash flows: £3,000 (years 1-3), £4,000 (years 4-5), £6,000 (year 6).
Investor's required return: 14%.
Firm's payback period: 3 years.
Payback period = 3.25 years (calculated by 3 + (1000/(4000)).
Decision: Reject the project based on the payback rule.
Note: NPV is £4,144 > 0.
Advantages of Payback Period
Easy to compute and understand, making it useful as a coarse screening tool.
Encourages cash generation.
Values early cash flows over late cash flows.
Disadvantages of Payback Period
Ignores the time value of money.
The choice of cutoff period is arbitrary.
Ignores cash flows after the cutoff period.
Biased towards rejecting long-lived projects, even if they have positive NPVs.
Biased towards accepting short-lived projects, even if they have negative NPVs.
Discounted Payback Period
Definition: The number of years required to recover the initial investment through DISCOUNTED accumulated future cash flows.
Addresses: Time value of money issue.
Example: Using the same cash flows as the payback period example.
Cash Flows: -£10,000 (t=0), £3,000 (t=1), £3,000 (t=2), £3,000 (t=3), £4,000 (t=4), £4,000 (t=5), £6,000 (t=6).
Internal Rate of Return (IRR)
Definition: The discount rate that results in a zero Net Present Value (NPV).
Example:
Using the same cash flow data.
IRR = 26.46%.
Decision Rule: Accept the project if IRR > Investor's required rate of return.
In this case, accept the project, since 26.46% > 14%.
NPV and IRR Relationship
For conventional investment projects (initial negative cash outflow followed by positive cash inflows):
Accept the project if IRR > r* (investor's required rate of return).
Both IRR and NPV provide the same accept/reject decision.
IRR does not indicate the increase to the value of the firm; it is a percentage.
Problems with IRR
Non-conventional Cash Flows: IRR does not work well with non-conventional cash flow projects (cash flows that change signs more than once).
Example:
Year 0: -£4,500; Year 1: £6,000; Year 2: £6,000; Year 3: -£8,000.
NPV is zero at both 15.47% and 33.3%, resulting in multiple IRRs.
Using a cutoff rate of 14% would lead to accepting the project, even though the NPV is negative on either side of the two IRRs.
Mutually Exclusive Projects: IRR may lead to incorrect decisions when comparing mutually exclusive projects (projects where only one can be chosen).
Example:
Project A: £1m investment, £1.2m cash flow in year 1. IRR = 20%.
Project B: £3m investment, £3.45m cash flow in year 1. IRR = 15%.
NPV Project A = = £71,429.
NPV Project B = = £80,357.
NPV suggests Project B is better, while IRR suggests Project A is better.
The crossover rate is 12.5%.
Accounting Rate of Return (ARR)
Definition: The ratio of the project’s average annual profits to the average annual book value of assets.
Also referred to as Average Accounting Return (AAR) or Book Rate of Return (BRR).
Example:
Initial investment in assets: £50,000
Year
Depreciation
Closing Book Value
Revenues less Operating Expenses
Depreciation
Earnings Before Tax
Taxes (33%)
Earnings for Ordinary
t=0
50,000
t=1
5,000
45,000
20,000
5,000
15,000
4,950
10,050
t=2
10,000
35,000
19,000
10,000
9,000
1,970
6,030
t=3
15,000
20,000
18,500
15,000
3,500
1,155
2,345
t=4
20,000
0
21,000
20,000
1,000
330
670
If target ARR = 12%, accept. If target ARR = 13%, reject.
Advantages of ARR
Easy to compute because the firm already collects accounting information for budgeting and planning.
Disadvantages of ARR
Ignores the time value of money.
The choice of target ARR is arbitrary.
Based on earnings, not cash flows.
Uses accounting depreciation.
Tax charge based on accounting earnings.
No standard calculation method.
Not a true return on investment.
Profitability Index (PI)
Definition: The ratio of the present value of future cash flows of a project to its initial investment.
Decision Rule: Accept a project if PI > 1.
Like IRR, PI does not work well when dealing with mutually exclusive projects.