| 变量 | (1) | (2) | (3) | (4) | 
| 回归结果 | 直接效应 | 间接效应 | 总效应 | |
| lnisu | 0.0883 | 0.0979 | −0.182** | −0.0838 | 
| (0.0909) | (0.0915) | (0.221) | (0.146) | |
| lngdp | −0.0952*** | −0.0994*** | 0.000578 | −0.0989 | 
| (0.0307) | (0.0270) | (0.0610) | (0.0699) | |
| lnei | 0.958*** | 0.960*** | −0.0158 | 0.944*** | 
| (0.0330) | (0.0343) | (0.0549) | (0.0685) | |
| lnopen | 0.0114 | 0.00995 | 0.0688* | 0.0787 | 
| (0.0228) | (0.0248) | (0.0424) | (0.0571) | |
| lnurban | 0.0490 | 0.0426 | 0.0560 | 0.0987 | 
| (0.0377) | (0.0408) | (0.0603) | (0.0672) | |
| lntech | 0.0634 | 0.0684 | −0.0444 | 0.0240 | 
| (0.0458) | (0.0432) | (0.0863) | (0.106) | |
| W × lnisu | −0.225** (0.359) | 
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| W × lnopen | 0.0858* (0.0512) | 
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| Sigma2_e | 0.00253*** (0.000327) | 
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| R2 | 87.5% | 
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