| 变量 | GTI | GTI | GTI | GTI | 
| (1) | (2) | (3) | (4) | |
| treat × post | -0.0506*** (0.0182) | -0.0677*** (0.0242) | -0.524*** (0.109) | -0.562*** (0.147) | 
| Sub × treat | 
 | 
 | -0.00624** (0.00307) | -0.0106*** (0.00405) | 
| Sub × treat × post | 
 | 
 | 0.0265*** (0.00860) | 0.0324*** (0.0114) | 
| Sub × post | 
 | 
 | 0.00906*** (0.00332) | 0.00769* (0.00442) | 
| Sub | 
 | 
 | 0.0312*** (0.00620) | 0.0161** (0.00774) | 
| Growth | 
 | 0.0616 (0.0521) | 
 | 0.0782 (0.0526) | 
| Lev | 
 | -0.0947 (0.0716) | 
 | 0.0378 (0.0747) | 
| Ros | 
 | -0.319*** (0.120) | 
 | -0.121 (0.122) | 
| size | 
 | 0.0704*** (0.0133) | 
 | 0.0347** (0.0158) | 
| age | 
 | -0.0327** (0.0159) | 
 | -0.0566*** (0.0159) | 
| TobinQ | 
 | 0.0506*** (0.0154) | 
 | 0.0537*** (0.0156) | 
| 企业 | 控制 | 控制 | 控制 | 控制 | 
| 年度 | 控制 | 控制 | 控制 | 控制 | 
| 样本量 | 4400 | 4400 | 4400 | 4400 | 
| 调整R2 | 0.002 | 0.022 | 0.035 | 0.047 |