st: RE: generate a new categorical variable

["Sarah Edgington" <sedging@ucla.edu>]

Your code looks like it should work. 
My first thought is that you should double check that the data really looks
like what you expect.  I'd start with a cross-tabulation of Y and Z.  For
your code to work it has to be true that Y==1 when Z takes the B, C, and D
values.  Likewise, you want to be sure that you have all the values for Z
(and that they're capitalized as shown and don't include spaces).
-Sarah

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of urbain thierry
YOGO
Sent: Thursday, September 13, 2012 12:54 PM
To: statalist@hsphsun2.harvard.edu
Subject: st: generate a new categorical variable

Dear all
i have two variables Y and Z. Y is a dummy variable which takes 1 if
individual has access to water and 0 otherwise. Z is a categorical variable
which has the following structure:
Z=A if individual uses bleach to clean water Z=B if individual use a filter
to clean water Z=C if individual use solar energy to clean water Z=D if
individual use absorbent cotton to clean water

Here is my problem. I want to generate a new variable X which should be a
combination of Y and Z. Here is the code i have written gen X=0 if Y==0
replace X=1 if Y==1 & Z=="A"
replace X=2 if Y==1 & Z=="B"
replace X=3 if Y==1 & Z=="C"
replace X=4 if Y==1 & Z=="D"

My concern is that when i write this code, the first two lines work, but
after, there is 0 replacement. Please can somebody help me? Thank

--
*Urbain Thierry YOGO
Ph.D candidate in Economics*
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