Table 3.
Model results of government costs by region. Tti is the testing interval, in months; NWHT is the number of whole-herd tests required for the herd to clear quarantine. The historical government test-and-removal plan is as described in (USDA:APHIS:VS, 2005). All costs are thousands of US dollars per herd detected. A depopulation preference is noted when the cost of depopulation is predicted to be smaller than the cost of test-and-removal for that iteration; the depopulation preference is reported from the constrained optimal control strategy.
| Region | Unconstrained Government Optimal Tti, Nwht | Constrained1 Government Optimal Tti, Nwht | Unconstrained Optimal Government Cost (range) | Constrained1 Optimal Government Cost (range) | Historical Government Cost (range) | Government Depopulation Cost (range) | Herds with Depopulation Preference /herd detected (proportion) |
|---|---|---|---|---|---|---|---|
| National | 2,2 | 3,2 | 14.01 (2.13;68.9) | 13.77 (2.07;71.82) | 27.26 (12.5;65.7) | 25.87 (6.99;43.73) | 190/662 (0.29) |
| Heartland | 2,2 | 2,2 | 14.13 (2.77;57.14) | 14.48 (2.75;48.11) | 23.41 (9.27;64.24) | 27.39 (10.6;40.49) | 133/630 (0.21) |
| Northern Great Plains | 3,2 | 4,2 | 19.39 (2.86;66.65) | 19.57 (2.81;75.91) | 44.75 (21.57;80.13) | 46.45 (5.17;72.8) | 173/636 (0.27) |
| Prairie Gateway | 2,2 | 3,2 | 17.77 (3.62;73.37) | 17.85 (3.79;107.28) | 33.14 (15.09;73.35) | 38.72 (13.95;58.6) | 133/652 (0.2) |
| Eastern Uplands | 3,2 | 3,2 | 6.17 (−2.16;46.56) | 6.24 (−1.32;32.28) | 16.74 (4.96;39.63) | 3.31 (−14.25;18.55) | 378/651 (0.58) |
| Basin and Range | 2,2 | 4,2 | 29.03 (4.77;131.8) | 29.1 (5.18;91.96) | 63.36 (31.82;121.85) | 74.69 (19.36;110.7) | 135/663 (0.2) |
| Mississippi Portal | 3,2 | 4,2 | 7.71 (−0.59;38.03) | 7.64 (−0.74;38.52) | 17.87 (6.38;45.72) | 7.1 (−7.71;20.01) | 354/627 (0.56) |
| Southern Seaboard | 3,2 | 3,2 | 10.54 (1.72;51.95) | 10.5 (1.77;44.22) | 19.66 (7.96;48.58) | 14.34 (1.25;26.67) | 290/628 (0.46) |
| Fruitful Rim | 3,2 | 3,2 | 16.9 (3.12;76.42) | 16.95 (3.11;93.7) | 34.28 (15.5;82.71) | 26.7 (8.02;60.17) | 195/647 (0.3) |
1
Constrained optimal solutions rejected control plans resulting in false clearance of an infected herd in a given iteration.