Date: Thu, 17 Apr 1997 17:01:55 GMT
Reply-To: Edward Malthouse <ecm@NWU.EDU>
Sender: "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From: Edward Malthouse <ecm@NWU.EDU>
Organization: Northwestern University
Subject: missings in Boolean expressions
It seems that sas treats missing values as being less than any number, e.g.,
if x < 10 then lt10 = 1;
if x > 10 then gt10 = 1;
proc print; run;
OBS X LT10 GT10
1 . 1 .
The expression ". < 10" is true. Can anyone explain the rationale for this?
If we don't have data for something, how can we say that its value is less
Department of Marketing