st: Strange behavior or bug? - svy : total returns different results in Stata versons 9, 10 and 11

[Zurab Sajaia <zsajaia@hotmail.com>]

Dear all,
 
I've encountered a strange behavior of -svy- commands and was wandering whether this is a bug or I'm doing something wrong, any thought would be greatly appreciated.
 
the setup:
 
sysuse auto, clear
svyset [pw = weight]
 
generate mv = .
 
svy : total mv
 
all versions (I have) of Stata (9-11) return -no observation- error after this.
 
 
but if we change weights:
 
replace weight = 0 in 1/5  // there might be other explanation but I found that this 
                           // error happens only if I have some observations with zero weights
 
then Stata 9 still shows error 2000 but both 10 and 11 versions return an output with "(sum of weights equals zero)" message on the screen and e(b) matrix equal to 0.
 
 
Has anyone else encountered the similar thing?
Thanks,
Zurab
 
 
 
 
 
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