面板数据,固定效应模型,自变量是连续变量,加入了自变量和一个二值虚拟变量(发达国家和发展中国家)的交互项,自变量显著,交互项不显著。如果进行分样本回归,发展中国家组自变量非常显著(1%),发达国家组自变量完全不显著,也就是说自变量的效应在两个组别明显是有差别的,但为何交互项系数不显著呢?求解答。
表在这里 (第二行是交互项,第二列是发达国家样本,第三列是发展中):
| | (1) | (2) | (3) |
| | gini_net | gini_net | gini_net |
| finreform | 0.1395*** | -0.0298 | 0.0987** |
| | (0.0509) | (0.0821) | (0.0473) |
| developed*finreform | -0.1083 | | |
| | (0.0747) | | |
| rgdp | 0.0002** | 0.0003*** | 0.0001* |
| | (0.0001) | (0.0001) | (0.0001) |
| rgdp2 | -0.0000 | -0.0000** | -0.0000 |
| | (0.0000) | (0.0000) | (0.0000) |
| inflation | 0.0001 | 0.0049* | 0.0003** |
| | (0.0002) | (0.0026) | (0.0001) |
| govfc | 0.0044 | -0.2033*** | 0.1485*** |
| | (0.0504) | (0.0652) | (0.0549) |
| edu | -0.0261 | -0.0611 | -0.0241 |
| | (0.0236) | (0.0496) | (0.0231) |
| trade | 0.0029 | -0.0216 | 0.0093 |
| | (0.0085) | (0.0136) | (0.0108) |
| unemp | 0.0863*** | 0.1425** | 0.0601 |
| | (0.0323) | (0.0525) | (0.0401) |
| urban | 0.0323 | -0.0666 | 0.1033 |
| | (0.0906) | (0.0602) | (0.1206) |
| gdpgrowth | -0.0115 | -0.0436 | 0.0027 |
| | (0.0151) | (0.0354) | (0.0143) |
| depratio | 0.0515* | 0.1294* | 0.0641* |
| | (0.0287) | (0.0651) | (0.0330) |
| _cons | 31.0033*** | 34.1936*** | 30.3019*** |
| | (6.4580) | (6.6579) | (8.0883) |
| N | 1235 | 527 | 708 |
| adj. R2 | 0.207 | 0.377 | 0.219 |