Table 4.
Robustness Results with Control Variables Added
| Model Variable | (1) | (2) | (3) | (4) |
|---|---|---|---|---|
| Comprehensive Technical Efficiency | Scale Efficiency | Comprehensive Technical Efficiency | Scale Efficiency | |
| Difference-in-differences variable | 0.14*** | 0.18*** | 0.14* | 0.18*** |
| Urbanization | 0.34 | 0.45 | 0.34 | 0.45 |
| Economic development levellogarithm | 0.07*** | 0.08*** | 0.07*** | 0.08*** |
| Industrial structure | −1.06*** | −1.02*** | −1.06*** | −1.02*** |
| Population density logarithm | *** | −0.12 | −0.21*** | −0.12** |
| Natural population growth rate | 0.00 | 0.01* | 0.00 | 0.01 |
| Constant term | 1.99*** | 1.54*** | 1.99*** | 1.54*** |
| Sample volume | 451 | 451 | 451 | 451 |
| Goodness of fit | 0.14 | 0.15 | 0.14 | 0.15 |
| Section number | 41 | 41 | 41 | 41 |
Notes: *p< 0.005, **p<0.01, ***p<0.0001.