Estimated WTP Values (€/Household/Year) Based on the Three Random Utility Choice Models
| Water Quality Scenario | Basin | RPL Model 1 | RPL Model 2 | Latent Class | Poe Testa | ||||
|---|---|---|---|---|---|---|---|---|---|
| WTP | 95% CI | WTP | 95% CI | WTP | 95% CI | p | Reject Equality? | ||
| Implicit prices | |||||||||
| Poor → Moderate | Campiña | 48.9 | 37.8–60.5 | 45.2 | 29.1–62.5 | 31.4 | 5.7–57.0 | 0.638 | No |
| Poor → Good | Campiña | 59.5 | 46.4–73.1 | 58.6 | 41.7–76.9 | 63.8 | 44.8–82.8 | 0.523 | No |
| Poor → Very good | Campiña | 80.3 | 67.6–93.4 | 65.4 | 48.3–86.3 | 84.0 | 60.8–107.2 | 0.866 | No |
| Moderate → Good | Valle | 42.8 | 31.1–54.6 | 37.6 | 21.6–55.9 | 61.7 | 40.4–83.0 | 0.658 | No |
| Moderate → Good | Doñana | 9.6 | −1.9 to 20.4 | 10.5 | −7.4 to 26.9 | 29.3 | 8.6–50.0 | 0.470 | No |
| Moderate → Very good | Valle | 54.5 | 43.6–66.4 | 41.7 | 24.8–59.0 | 83.8 | 57.0–110.5 | 0.871 | No |
| Moderate → Very good | Doñana | 13.4 | 2.2–25.0 | 34.3 | 17.9–51.3 | 32.7 | 5.9–59.5 | 0.050 | Yes |
| Good → Very good | Alto | 10.5 | 1.3–19.0 | 13.9 | −0.7 to 27.6 | 23.5 | −1.0 to 48.0 | 0.348 | No |
| Compensating surplus | |||||||||
| Current → Good | Whole | 102.3 | 83.0–122.7 | 135.0 | 102.4–172.1 | 130.5 | 86.0–175.0 | 0.074 | No |
| Current → Very good | Whole | 158.7 | 134.5–184.7 | 211.9 | 169.0–257.3 | 225.4 | 158.4–292.3 | 0.034 | Yes |
Note: RPL, random parameters logit; WTP, willingness to pay.
↵a Test of the emprirical distribution of the WTP values estimated for the first and second RPL model (Poe, Giraud, and Loomis 2005)