What is ".a" and ".c"?

What is ".a" and ".c"?

by Jennifer Rosenthal -

I know that a few of us in class have our own data that results in us seeing ".a" and ".c" appear in addition to the usual "." that indicates missing.

For those of us encountering these, I found the answer to what .a and .c represent...

.a = invalid

.c = inconsistent

Re: What is ".a" and ".c"?

by Mark Pletcher -

Right, these are codes that Stata uses for being more specific about what KIND of missing data you have.  For our purposes (and yours, when you are cleaning data), I believe that referring to these with a simple period (.) will be sufficient, such as:

gen ValueIsMissing = 0

replace ValueIsMissing = 1 if Value ==.

this should do the same as

replace ValueIsMissing = 1 if Value==.a | Value==.c

(unless you have other kinds of missing values other than .a and .c)

Hope that is clear!