求助两个问题————
1.固定效应因为多重共线性老是被omitted!所以我就改成了LSDV做固定效应,
输入reg Happiness Freedom Age Education Health Trust Religious Marital i.Number ,vce(cluster Number )
就显示——Number: factor variables may not contain noninteger values
r(452);
但是我看我的number都是整数值呀!我不理解该怎么改...暴风哭泣
2.然后我又改用多维固定reghdfe
输入 reghdfe Happiness Freedom Age Education Health Trust Religious Marital,absorb( Number )
出现no observations left after dropping singletons
这个有办法改嘛?