Additionality Estimates for the Effect of Nutrient Management Payments on Nutrient Management Practices
| Adoption Rates | |||||||
|---|---|---|---|---|---|---|---|
| Nonpayment Fields | Additionality | ||||||
| Optimal Kernel Bandwidth | Payment Fields | Matched | Nonmatched | Estimate | 95% Confidence Interval | ||
| Practice | (1) | (2) | (3) | (4) | (5) | (6) | (7) |
| Soil Test (% of fields) | |||||||
| Nitrogen | 0.06 | 0.44 | 0.24 | 0.24 | 0.19 | 0.04 | 0.34 |
| Phosphorus | 0.01 | 0.27 | 0.19 | 0.16 | 0.08 | –0.07 | 0.23 |
| Timing (% of nutrients applied in fall) | |||||||
| Nitrogen | 0.04 | 0.02 | 0.11 | 0.14 | –0.09 | –0.27 | –0.01 |
| Phosphorus | 0.01 | 0.12 | 0.10 | 0.22 | 0.02 | –0.29 | 0.26 |
| Method (% of nutrients broadcast without incorporation) | |||||||
| Nitrogen | 0.20 | 0.02 | 0.22 | 0.22 | –0.20 | –0.25 | –0.13 |
| Phosphorus | 0.03 | 0.08 | 0.23 | 0.27 | –0.15 | –0.33 | 0.11 |
| Application Rate (lbs. of nutrient) | |||||||
| Nitrogen | |||||||
| Corn | 0.02 | 100 | 103 | 122 | –3.2 | –37.7 | 36.7 |
| Wheat | 0.10 | 79 | 64 | 65 | 15.3 | 2.0 | 24.4 |
| Barley | 0.20 | 59 | 54 | 53 | 4.9 | –13.7 | 25.1 |
| Soybeans | 0.20 | 8.1 | 8.6 | 8.7 | –0.5 | –4.5 | 4.3 |
| Phosphorus | |||||||
| Corn | 0.01 | 20.8 | 36.9 | 46.8 | –16.1 | –30.5 | 2.5 |
| Wheat | 0.05 | 22.0 | 22.7 | 23.3 | –0.7 | –8.7 | 6.7 |
| Barley | 0.20 | 22.5 | 19.2 | 20.0 | 3.3 | –6.8 | 12.2 |
| Soybeans | 0.06 | 31.3 | 31.2 | 33.7 | 0.1 | –9.1 | 14.4 |
Note: The table reports mean estimates of the average treatment-effect-on-the-treated from a Gaussian kernel-based propensity score matching estimator with a bandwidth optimally determined under leave-out-one cross-validation. Survey-weighted results are representative of the U.S. fields and are obtained by calculating the weighted average difference in outcomes between treatment and matched control observations with observation-specific survey weights. The 95% confidence interval in determined by bootstrapping the additionality estimates.