Table 3.
Robustness test
| Variables | (1) | (2) | (3) | (4) |
|---|---|---|---|---|
| Theil index | Urban‒rural income gap | |||
| Integration | -0.078** | -0.013*** | -0.009** | -0.012*** |
| (0.032) | (0.003) | (0.004) | (0.003) | |
| Economic development | -1.241*** | -0.015 | 0.021 | -0.012 |
| (0.341) | (0.027) | (0.026) | (0.027) | |
| Industrial structure | 0.068*** | 0.003** | 0.003* | 0.003 |
| (0.022) | (0.002) | (0.002) | (0.002) | |
| Human capital | -5.418 | 0.771 | 0.969 | 0.777 |
| (9.202) | (0.869) | (0.915) | (0.876) | |
| Fiscal expenditure ratio | -1.353 | -0.052 | 0.037 | -0.054 |
| (1.130) | (0.071) | (0.070) | (0.071) | |
| Opening‒up | -1.487 | -0.074 | -0.072 | -0.116* |
| (0.945) | (0.061) | (0.062) | (0.059) | |
| Financial development | -0.355 | 0.003 | 0.006 | -0.002 |
| (0.248) | (0.016) | (0.016) | (0.016) | |
| Port distance × Time trend | -0.000 | |||
| (0.000) | ||||
| Constant | 15.903*** | 2.181*** | 1.785*** | 2.225*** |
| (3.412) | (0.283) | (0.284) | (0.283) | |
| City fixed effect | Yes | Yes | Yes | Yes |
| Time fixed effect | Yes | Yes | Yes | Yes |
| Observations | 1,712 | 1,957 | 1,668 | 1,979 |
| R-squared | 0.980 | 0.985 | 0.986 | 0.985 |
The values in parentheses represent clustered robust standard errors, with, *,** and *** indicating significance at the 10%, 5%, and 1% levels, respectively