st: Is pweight the right weight for me and how to specify my weight vector

[Jesse Burkhardt <jesse.burkhardt@yale.edu>]

Dear Members.
I have data with multiple observations per zip code.  I count the
number of observations per zip code and use that number as the
sampling weight. So I have a vector called weights, which is equal to
the number of observations per zip code. When I run a regression and
use the [pweight=weights] option, does stata invert each element of
the vector or am I supposed to do take the inverse manually?

Secondly, can someone provide some intuition for when I use pweight as
stated above?  Is the result a regression in which each zip code is
weighted equally?  The worry is that without this weight command, a
zip code with 10,000 observations will drive regression results more
than a zip code with 1 observation.  I'm wondering if using pweight
will down weight the zip code with 10,000 observations and upweight
zip codes with fewer observations. Is there a better weighting scheme
to use in this situation? Thanks for any advice.
Jesse
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