|
| (1) | (2) | (3) | (4) |
|
| tfp | tfp | tfp | tfp |
| did | 0.0465* | 0.0469** | 0.0400** | 0.0902 |
| (16.27) | (97.36) | (73.84) | (8.10) | |
| ln_size | −0.0546 | −0.0604 | −0.0292 | −0.331 |
| (−2.28) | (−10.97) | (−1.06) | (−1.25) | |
| ln_staff | −0.182*** | −0.182* | −0.181* | −0.151 |
| (−945.35) | (−32.96) | (−15.17) | (−5.21) | |
| ln_earning | 0.293 | 0.281* | 0.279 | 0.566 |
| (12.41) | (61.15) | (8.94) | (1.83) | |
| _cons | −3.666** | −3.335* | −3.922** | −3.703 |
| (−177.97) | (−48.62) | (−122.02) | (−3.64) | |
| 时间固定效应 | 是 | 是 | 是 | 是 |
| 个体固定效应 | 是 | 是 | 是 | 是 |
| N | 7709 | 2482 | 2822 | 163 |