st: From: John Singhammer <singhammer@gmail.com>

[owner-statalist@hsphsun2.harvard.edu]

Hi

I'm struggling with a problem that probably is easily solved.
Apparently not by me, so any advices will be greatly appreciated

The data looks like this: Children's height was measured at grade 0 and
grade 1.
Usually, you expect childrens height to increase. however, for id a19,
height decreased,  most likely due to measurement error



 id maxheight0 maxheight1 height grade
a19   130         .                 130       0
a19     .         126               126       1
y03    117         .                117       0
y03     .         127               127       1

I have 15.000 observation and wants to generate a variable of the
difference in height from grade 0 to grade 1. That way, I can delete or
correct those with a negative growth
I've managed to isolate the measures for each grade but the next step is a
mystery. Obviously, subtracting maxeighth1 from maxheight0 is not an obtion
at this point. How do I manage to illuminate the difference in
height between grades?

I'll be happy for any suggestion

Thanks

Kind regards
John
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