Date:         Tue, 5 Mar 2002 17:15:44 -0500
Reply-To:     Chun Ling Lu <cllu@HSPH.HARVARD.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Chun Ling Lu <cllu@HSPH.HARVARD.EDU>
Content-Type: text/plain; charset="us-ascii"; format=flowed

Hi all,

I have a problem in creating a interaction variable.
Example:
        id      ratio   working
        1       0.12    1
        2       0.67    0
        3       0.89    1

where ratio is continuous var, wroking is dummy.

I wanted to create rawork=ratio*working. However, using my dataset, I got
something like this

        id      ratio   working rawork
        1       0.12    1       0.13
        2       0.67    0       . (missing)
        3       0.89    1       0.89.

where rawork for id=2 is missing, which does not make sense.

I then pull out these obs with unreasonable missing values such as id=2
case, and created a new interaction variable with the same calculation:
raworknew=ratio*work, this time, it worked, I got things like this:

        id      ratio   working  rawork                raworknew
        2       0.67    0             . (missing)   0

Can anybody tell me what's going on?

Thanks.

Chunling