|
| (1) | (2) | (3) |
| 变量 | Lp法 | Lp法 | Lp法 |
| IPR | −1.013*** | −1.155*** | −1.154*** |
|
| (−179.71) | (−173.57) | (−173.66) |
| Pat |
|
| −0.021*** |
|
|
|
| (−3.89) |
| netprofit |
| 0.066*** | 0.067*** |
|
|
| (8.52) | (8.63) |
| size |
| 7.701*** | 7.990*** |
|
|
| (23.66) | (23.95) |
| Lev |
| 0.414*** | 0.408*** |
|
|
| (8.22) | (8.10) |
| Earning |
| −0.014 | −0.014 |
|
|
| (−1.39) | (−1.43) |
| First |
| −0.001 | −0.001 |
|
|
| (−0.92) | (−1.03) |
| TQ |
| 0.057*** | 0.056*** |
|
|
| (12.72) | (12.70) |
| ROA |
| 0.993*** | 1.003*** |
|
|
| (4.96) | (5.02) |
| Year | 控制 | 控制 | 控制 |
| Constant | 10.248*** | −14.493*** | −15.350*** |
|
| (365.55) | (−15.68) | (−16.17) |
| Observations | 8835 | 7977 | 7977 |
| R-squared | 0.968 | 0.976 | 0.977 |
| Number of code | 762 | 762 | 762 |
| Company FE | YES | YES | YES |
| F test | 0 | 0 | 0 |
| r2_a | 0.964 | 0.974 | 0.974 |
| F | 21,881 | 16,599 | 15,757 |