//How to generate dummy varaible in Stata
sysuse auto.dta,clear
sysdescribe auto.dta

tabulate rep78

//Using two step method
gen rep2=1 if rep78==2
replace rep2=0 if missing(rep2) & !missing(rep78)
browse rep78 rep2

//another way to doing it
gen rep3=0 if !missing(rep78)
replace rep3=1 if rep78==3
browse rep78 rep3

//Using one step method
gen rep4=rep78==4 if !missing(rep78)
browse rep78 rep4


gen repg=rep78>=3 if !missing(rep78)
browse rep78 repg

//Dummy variable for multiple categories
tabulate rep78, gen(dummy)
browse 

//Dummy variable using multiple condition

generate dummy= price<=6000 & rep78>=3 if !missing(price,rep78)
browse price rep78 dummy