Internal rates of return for selected treatment scenarios.
Scenario | Return (%) | |
---|---|---|
1. | A single investment now of $10 per tree will eliminate annual costs of $6 for 10 years | 58.9 |
2. | A single investment now of $20 per tree will eliminate annual costs of $6 for 10 years. | 27.0 |
3. | A $20 investment every 10 years will eliminate annual costs of $6. (Note reducing cost by $6 per year is equivalent to eliminating an annual cost of $6.) | 27.0 |
4. | A $10 investment now will eliminate a $30 cost in 5 years and an additional $30 cost in 10 years. | 30.4 |
5. | A $20 investment now will eliminate a $30 cost in 5 years and an additional $30 cost in 10 years. | 17.1 |
6. | When a period of 45 years is considered, a $100 investment per tree now will delay for 5 years a $300 cost normally occurring in 15 years, with additional $300 costs occurring every 8 or 9 years instead of every 5 years. | 10.2 |
7. | Same as scenario 6 except that recurring costs are $400. | 11.9 |
8. | Same as scenario 6 except that recurring costs are $500. | 13.3 |