Hello,

I want to write a code that creates a value which is the summation of several rows. I have negative values in my data and I want to ignore those values in the summation. I have run the following code but it is giving me missing values.

local x owe1 owe2 owe3 owe4
foreach x in `x'{
gen loan_1998= owe1+ owe2+ owe3+ owe4 if `x'>0

}

Here is how my data is looking like: it is a survey data and the the value -4 corresponds to a valid skipped.
PUBID SEX BDATE_M BDATE_Y CV_SAMPLE_TYPE RACE_ETHNICITY owe1 owe2 owe3 owe4 owe_1998
96 Male 2982616 1982 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
97 Male 2982616 1980 Cross-sectional Hispanic -4 -4 -4 -4 .
98 Male 2982616 1980 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
99 Male 2982616 1982 Cross-sectional Hispanic -4 -4 -4 -4 .
100 Female 2982616 1981 Cross-sectional Black -4 -4 -4 -4 .
101 Female 2982616 1981 Cross-sectional Black -4 -4 -4 -4 .
102 Female 2982616 1982 Cross-sectional Hispanic -4 -4 -4 -4 .
103 Female 2982617 1983 Cross-sectional Hispanic -4 -4 -4 -4
104 Female 2982617 1980 Cross-sectional Non-Black / Non-Hispanic -4 1500 -4 -4 .
105 Male 2982617 1983 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
106 Male 2982617 1981 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
107 Female 2982617 1982 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
108 Male 2982617 1984 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
109 Female 2982616 1982 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
110 Female 2982616 1984 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
111 Female 2982616 1981 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
112 Female 2982616 1984 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
113 Male 2982616 1984 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
114 Female 2982616 1982 Cross-sectional Non-Black / Non-Hispanic -4 -4 -4 -4 .
115 Female 2982617 1984 Cross-sectional Hispanic -4 -4 -4 -4 .
116 Male 2982617 1984 Cross-sectional Black -4 -4 -4 -4 .
I am wondering if someone can please help me figure out what is wrong?

Thank you for your assistance!