Hello everyone,

I have a question since i need 3 dummy variables there must be always one dummy variable omitted, which becomes the constant. Now my question is how can I formulate this in stata?
I have created 2 dummy variables low and high and i would like to do xtreg for medium also but i dont know how I can do that? My professor told me it will become the constant and dont need to recreate another dummy variable for it. Im a bit lost maybe someone could help me here?

code:

Code:
 //L Low M Medium H high
. gen Built_L= Built_area<18.27

. gen Built_H= Built_area>25.981

. gen Built_M= 1 - Built_L - Built_H

.
. gen Agri_L= Agri_area<48.90

. gen Agri_H= Agri_area>54.75

. gen Agri_M= 1-Agri_L-Agri_H     

.
. gen Forest_L= NaturalForest_area<7.3

. gen Forest_H= NaturalForest_area>15.82

. gen Forest_M= 1-Forest_H-Forest_L

.
. gen low_dev = Built_L & Agri_H & Forest_H

. gen high_dev = Built_H & Agri_L & Forest_L