Table 8.
Robustness test results.
| Variables | (13) |
(14) |
(15) |
(16) |
(17) |
(18) |
(19) |
(20) |
|---|---|---|---|---|---|---|---|---|
| Replacement of explanatory variables | Winsorize | |||||||
| SER | −0.003**(0.001) | −0.018 (0.012) |
−0.004*** (0.001) |
−0.003 (0.003) |
||||
| SER2 | 0.001 (0.001) |
−0.000 (0.000) |
||||||
| DIG | −0.001 (0.001) |
−0.004**(0.002) | 0.001 (0.001) |
−0.005*** (0.001) |
||||
| DIG2 | 0.001** (0.000) |
0.003*** (0.001) |
||||||
| Control variables | YES | YES | YES | YES | YES | YES | YES | YES |
| Year fixed | YES | YES | YES | YES | YES | YES | YES | YES |
| Individual fixed | YES | YES | YES | YES | YES | YES | YES | YES |
| Adj-R2 | 0.556 | 0.609 | 0.611 | 0.612 | 0.559 | 0.673 | 0.477 | 0.528 |
| Log-likelihood | 52.783 | 52.839 | 52.286 | 52.387 | 418.243 | 423.672 | 414.247 | 417.724 |
| F statistic | 8.38 | 9.73 | 14.05 | 18.33 | 8.8 | 9.77 | 15.3 | 11.82 |
| Obs | 231 | 231 | 231 | 231 | 231 | 231 | 231 | 231 |