/* What about a variable with five categories? */
reg realrinc tech-oper if year==2006
adjust if year==2006, by(occ80a) format(%9.1fc)

reg realrinc tech-oper men if year==2006
adjust if year==2006, by(occ80a men) format(%9.1fc)

reg realrinc tech-oper men white if year==2006
adjust if year==2006, by(occ80a men white) format(%9.1fc)


/* Omit another category */
reg realrinc tech-oper if year==2006
adjust if year==2006, by(occ80a) format(%9.1fc)

reg realrinc prof tech farm oper if year==2006
adjust if year==2006, by(occ80a) format(%9.1fc)