我想run一條regression
eviews : near singular matrix
我知道可以減少variables或者增加samples
但是這些都不適用
我條regression是
per capita GDP = c investment labor force road density (road density)*2 railway density (railway density)*2
因我想得出nonlinear 的result(substitution effect or expansion effect)
請問可以怎麼辦?有沒有其他方法?
我已用PANEL DATA, 各地區數據
Eviews是不是不能運算SQUARE TERM?
Thanks a lot!