Issues with variable categorization while subsetting a dataset

[nballred1]

I am currently trying to run a macro called PROCESS by Hayes which is used to test moderation and mediation models. However I keep running into the following errors:

It appears that the error might be due to the fact that my categorical variables are currently string values (words such as "yes" or "no"). When I change the values of these variables to numbers (0 and 1) manually in excel the macro works fine. However, I get the same error when I try to recode the values of the variables in SAS using the subset command. My subsetting code looks like this:

I would expect that my subsetting code should have the same effect as manually changing the values in excel before importing the data into SAS; however, it appears that SAS is treating them differently. If you have any advice on how I can recode my variables in SAS and have them work the macro I am using I would appreciate the help.

Thanks for the help.

[Astounding · Accepted solution]

When running a SAS program, you have to read the log.  There are messages that you ignored about numeric to character conversion.  What happens ...

You can't change a variable from being character to being numeric.  Once it's character, it remains character.  You can jump through the right hoops to get around that:

data subset;
   set study;
   if scarce = 'yes' then sc = 1;
   if scarce = 'no' then sc = 0;
   if purchase = 'yes' then pu = 1;
   if purchase = 'no' then pu = 0;
   drop scarce purchase;
   rename sc = scarce pu = purchase;
run;

This program in effect gives you new numeric variables.  You can then use DROP and RENAME to keep them under the original names, as numeric.  This version of the data should work.