Table 3.
Estimated coefficients for the frequency of insecticide sprays against cotton aphid, mirid bugs, and cotton bollworm
| No. of insecticide applications against each pest | |||
| Explanatory variables | Cotton aphid | Mirid bugs | Cotton bollworm |
| Infestation level: category II | 0.438*** | 0.929*** | 0.540* |
| (0.159) | (0.173) | (0.281) | |
| Infestation level: category III | 1.095*** | 1.641*** | 1.440*** |
| (0.248) | (0.185) | (0.331) | |
| Infestation level: category IV | 2.059*** | 2.679*** | 2.343*** |
| (0.324) | (0.282) | (0.404) | |
| Infestation level: category V | 2.598*** | 3.731*** | 4.685*** |
| (0.373) | (0.585) | (0.451) | |
| Share of Bt cotton area in total cotton area, % | 0.004 | 0.008*** | −0.017*** |
| (0.003) | (0.003) | (0.005) | |
| Constant | 1.943*** | −0.223* | 5.314*** |
| (0.380) | (0.126) | (0.737) | |
| Observations | 1,228 | 1,228 | 1,228 |
| R2 | 0.704 | 0.771 | 0.779 |
| Adjusted R2 | 0.684 | 0.755 | 0.764 |
Notes: (i) SEs are in parentheses. ***P < 0.01, **P < 0.05, and *P < 0.1. (ii) Infestation level I is the reference category for the infestation level explanatory variables. (iii) Estimated coefficients for dummy variables for counties and years are reported in SI Appendix, Table S4.