| (1) | (2) | (3) | (4) | (5) | (6) | |
| Patent | Invent | Cite | Patent | Invent | Cite | |
Differ | 5.414* | 6.512*** | 9.242*** | 7.920*** | 7.067*** | 8.315*** | |
| (1.876) | (2.605) | (4.250) | (3.148) | (3.102) | (4.157) | |
Board_size | −0.176 | 0.589 | −5.793* | −0.383 | 0.510 | −1.735 | |
| (−0.266) | (1.404) | (−1.852) | (−0.568) | (1.194) | (−0.546) | |
Idpt | 0.068 | 0.556* | −0.475 | 0.320 | 0.798*** | −0.040 | |
| (0.212) | (1.792) | (−1.121) | (1.013) | (2.597) | (−0.100) | |
Size | 0.317*** | 0.308*** | 0.527*** | 0.343*** | 0.350*** | 0.490*** | |
| (20.185) | (20.111) | (25.193) | (20.667) | (21.734) | (23.306) | |
Lev | −0.097 | −0.304*** | −0.636*** | −0.084 | −0.270*** | 0.081 | |
| (−0.926) | (−2.989) | (−4.580) | (−0.786) | (−2.590) | (0.595) | |
ROA | 0.070 | 1.786** | −0.478 | −0.587 | 0.925 | −1.456 | |
| (0.090) | (2.373) | (−0.465) | (−0.763) | (1.237) | (−1.494) | |
ROE | 0.973** | 0.011 | −0.216 | 1.468*** | 0.555 | 1.130** | |
| (2.438) | (0.028) | (−0.408) | (3.675) | (1.431) | (2.234) | |
Growth | −0.104** | −0.015 | −0.035 | −0.084* | −0.023 | −0.159** | |
| (−2.084) | (−0.308) | (−0.527) | (−1.668) | (−0.470) | (−2.491) | |
Dual | 0.055 | 0.071** | 0.006 | 0.047 | 0.065** | −0.034 | |
| (1.622) | (2.150) | (0.139) | (1.398) | (2.001) | (−0.794) | |
FirmAge | −0.072* | −0.069* | 0.853*** | −0.102** | −0.114*** | 0.334*** | |
| (−1.714) | (−1.705) | (15.342) | (−2.304) | (−2.638) | (5.931) | |
常数项 | −3.985*** | −5.111*** | −9.907*** | −5.366*** | −6.525*** | −9.805*** | |
| (−11.653) | (−15.350) | (−21.785) | (−13.466) | (−16.855) | (−19.432) | |
Ind | 未控制 | 未控制 | 未控制 | 控制 | 控制 | 控制 | |
Year | 未控制 | 未控制 | 未控制 | 控制 | 控制 | 控制 | |
N | 7986 | 7986 | 7986 | 7986 | 7986 | 7986 | |
AdjustedR2 | 0.090 | 0.089 | 0.162 | 0.112 | 0.114 | 0.258 |