Table 3 Robustness test.
Variable | Panel 1: Consider sample selection and exclusion policies | Panel 2: Substitution of explanatory variables | Panel 3: Replacement of control variables | ||||
---|---|---|---|---|---|---|---|
(1) | (2) | (3) | (4) | (5) | (6) | (7) | |
DID | 2.199** | 3.632*** | 3.686** | 0.127*** | 0.043*** | 3.514*** | 1.382** |
(0.903) | (1.061) | (1.739) | (0.044) | (0.006) | (0.738) | (0.790) | |
Control variable | YES | YES | YES | YES | YES | YES | YES |
N | 3024 | 2881 | 2552 | 3112 | 2552 | 3,123 | 2,552 |
R-squared | 0.407 | 0.410 | 0.280 | 0.794 | 0.645 | 0.280 | 0.461 |
Urban Effect | YES | YES | YES | YES | YES | YES | YES |
Time Effect | YES | YES | YES | YES | YES | YES | YES |