stata面板数据回归后提取残差用哪个代码?是predict var,ue还是predict var,u、predict var,e?有解释这样,那么固定或者随机模型回归是用u?
xb xb, fitted values; the default
stdp calculate standard error of the fitted values
ue u_i + e_it, the combined residual
* xbu xb + u_i, prediction including effect
* u u_i, the fixed- or random-error component
* e e_it, the overall error component