generate dummy variable with two if conditions

[Thomas Hall]

Hello everyone,

i have a data set with the two dummy variables date4 and statementdum. I want to create a new dummy variable which is 1 if date4=1 and statementdum=1 and 0 if date 4=1 and statementdum=0.

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(date4 statementdum)
1 1
0 1
0 1
0 1
0 0
1 0
0 1
0 0
0 0
0 1
end

I have already tried this code, but it gives the new dummy variable a 1 if one of the two conditions is true.

gen date4k=.
replace date4k=1 if date4==1
replace date4k=1 if statementdum==1
replace date4k=0 if date4==0
replace date4k=0 if statementdum==1



many greetings
Thomas

[Joseph Coveney]

You haven't exhausted the possibilities in you specification.

Maybe start with something like this

generate byte date4k = date4 & statementdum if !mi(date4, statementdum)

then take a look and go from there to flesh it out the way you want.

[Thomas Hall]

I found another way for the right solution:

gen date4k=1 if date4==1 & knowledgedum==1
replace date4k=0 if date4==1 & knowledgedum==0

thanks for your help Joseph

[Nick Cox]

gen date4k = knowledgedum if date4 == 1

is one line not two.