| Dependent Variation | (1) without controls | (2) without controls | (3) with controls | (4) with controls |
| Lnk | 0.5487*** | 0.0903*** | 0.3878*** | 0.1009*** |
|
| (0.0324) | (0.0151) | (0.0182) | (0.0168) |
| LnH | −0.0570* | −0.0992*** | −0.1594*** | −0.0928*** |
|
| (0.0335) | (0.0330) | (0.0179) | (0.0337) |
| Internet index | 1.8524*** | 0.2073* | 0.9413*** | 0.2500** |
|
| (0.1867) | (0.1091) | (0.1193) | (0.1165) |
| Market index |
|
| 0.0937*** | 0.0169** |
|
|
|
| (0.0069) | (0.0082) |
| Lntech |
|
| 0.4257*** | 0.0136 |
|
|
|
| (0.0125) | (0.0553) |
| Lntrans |
|
| −0.4292*** | −0.0244 |
|
|
|
| (0.0149) | (0.0605) |
| Constant | 3.2580*** |
| 2.4209*** |
|
|
| (0.1999) |
| (0.1356) |
|
| Fixed effects | no | yes | no | yes |
| N | 450 | 450 | 450 | 450 |
| adj. R2 | 0.898 | 0.994 | 0.974 | 0.994 |