| 变量 | (1) | (2) | (3) | (4) |
| lnEXP | lnEXP | lnEXP | lnEXP | |
| TFI | 1.956** | 0.394 | 3.569*** | 2.156*** |
|
| (2.58) | (0.69) | (5.18) | (3.67) |
| lnGDP |
| 0.623*** | 0.293*** | 0.488*** |
|
|
| (11.98) | (4.37) | (8.24) |
| lnPOP |
|
| 0.490*** | 0.285*** |
|
|
|
| (6.81) | (4.50) |
| lnDIS |
|
|
| −0.617*** |
|
|
|
|
| (−8.98) |
| Constant | 12.019*** | 8.912*** | 0.399 | 11.673*** |
|
| (24.08) | (19.83) | (0.30) | (7.05) |
|
|
|
|
|
|
| Observations | 170 | 170 | 170 | 170 |
| R-squared | 0.038 | 0.483 | 0.596 | 0.728 |
| country FE | YES | YES | YES | YES |
| F test | 0.0106 | 0 | 0 | 0 |
| r2_a | 0.0325 | 0.477 | 0.589 | 0.722 |
| F | 6.676 | 77.97 | 81.60 | 110.7 |