Table 1.
Number | Model | Diminishing returns? | Asymptote? |
---|---|---|---|
1 | P = a + bV | No | No |
2 | P = a + (b/V) | Yes | Yes (a) |
3 | P = a + bD | No | No |
4 | P = a + (b/D) | Yes | Yes (a) |
5 | P = a + b(V + D) | No | No |
6 | P = a + (b/(V + D)) | Yes | Yes (a) |
Models 2, 4 and 6 assume that control costs are greater than 0 and show diminishing returns and an asymptote (a).