| (a) | (b) | (c) | (d) |
dlInvention | lInvention | lInvention | lInvention | |
L.inde_com | 0.795*** | 0.395 | 0.395 | 0.395 |
| (3.08) | (1.46) | (1.08) | (0.87) |
L.log_Total | 0.515*** | 0.400*** | 0.400*** | 0.404*** |
| (29.97) | (12.88) | (6.47) | (6.28) |
L.cap_exp | 0.671*** | 0.359* | 0.359 | 0.356 |
| (2.85) | (1.68) | (1.31) | (1.01) |
L.Leverage | −0.000203* | 0.000619 | 0.000619*** | 0.000689*** |
| (−1.70) | (1.34) | (6.11) | (10.55) |
L.Borad_size | 0.0432*** | 0.0212** | 0.0212 | 0.0334* |
| (5.04) | (2.11) | (1.26) | (1.88) |
L.logQ | 0.0747*** | 0.0225*** | 0.0225*** | 0.0185* |
| (4.35) | (3.01) | (2.99) | (1.89) |
year_pre2003 |
|
| −0.000396** | −0.000385** |
|
|
| (−2.26) | (−2.25) |
_cons | −11.48*** | −8.895*** | −8.104*** | −8.304*** |
| (−23.40) | (−12.78) | (−5.97) | (−5.90) |
N | 8185 | 8185 | 8185 | 8185 |
r2 | 0.218 | 0.219 | 0.219 | 0.220 |
Year fixed effects | Yes | Yes | Yes | Yes |
Firm fixed effects | No | Yes | Yes | Yes |
Trend control | No | No | Yes | Yes |
Control*bill | No | No | No | Yes |