Hi,

I have noticed that when I run the following, they produce exactly similar results for coefficients, SE and residuals. However, their predicted yhats are not similar and this is due to different constents.

My question is
If I need to use predicted yhat, not the residuals, which model will I use? And how will I know that whatever I am choosing is the correct one for yhat?

sysuse auto, clear
xtset rep


regress price mpg weight length i.rep i.trunk
predict ccc1
areg price mpg weight length i.trunk, absorb(rep)
predict ccc
reghdfe price mpg weight length, absorb (rep trunk)
predict ccc2



regress price mpg weight length i.rep i.trunk
predict bbb1, residuals
areg price mpg weight length i.trunk, absorb(rep)
predict bbb, residuals
reghdfe price mpg weight length, absorb (rep trunk) resid