| 变量 | Maintain | |||
|---|---|---|---|---|
| 模型(1) | 模型(2) | 模型(3) | 模型(4) | |
| Migration | 0.0343***(0.0052) | 0.0119*(0.0066) | 0.0215***(0.0066) | |
| Density | 14.0775***(0.1071) | 14.5398***(0.129) | 14.5946***(0.1277) | |
| Migration×Density | -0.0981***(0.0176) | -0.1224***(0.0176) | ||
| Trade | -0.0346***(0.0063) | |||
| FDI | -0.0034(0.0166) | |||
| Total_pat | 0.0830***(0.0047) | |||
| “国家—时段”控制 | YES | YES | YES | YES |
| “技术—时段”控制 | YES | YES | YES | YES |
| N | 16445 | 16445 | 16445 | 16445 |
| R2 | 0.247 | 0.660 | 0.662 | 0.670 |
