> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Do, Phoenix
> Sent: 07 March 2004 21:35
> To: [email protected]
> Subject: RE: st: gini coeff
>
>
> Stephen,
>
> Thank you for your explanations. My understanding now is:
>
> 1. STATA's ginides command assumes that the all your obs are
> in 1 population. So if I wanted to treat each county as a
> separate population and calculate gini indices for each tract
> within a county, I would have to qualify the command with an
> "if county" or "by county" statement. (I tried this and STATA
> is giving me an error). Is there another way to do this
> besides using subsets of your data and then appending them?
>
> 2. Your code treats each tract as a population. Thus, the
> income distribution of one tract will not influence the gini
> of another tract.
>
> 3. your ineqdeco command would give the same results as the
> ginidesc command
>
> Is this right? Or am I confused.
I admit that /I/ am confused because you don't state clearly enough (for
me)
what it is that you really want to do; nor did you do so in your first
message.
But anyway, here goes ...
Re Q1: I don't know why you get an error using -if- option with
-ginidesc-:
contact the authors. I don't understand the statement about doing
separately and
appending -- the sample code I gave you showed how to get tract-specific
indices
in the current data set
Q2. Yes. By definition, to calculate the subgroup Gini, you use data
from that subgroup.
Q3. I cannot speak for -ginidesc-; I do not know the answer. But
-indeqdeco- and -inequal7- give correct answers as far as I know, and
the same answer.
To reiterate what I said last time: which program you want to use
depends on your goal. If you just want the tract-specific Ginis, you can
use -indeqdeco- in the ways I discussed last time. If you want to
decompose the Gini into within/between/overlapping terms, use
-ginidesc-.
Moreover you needed to provide more information about the nature of your
data. (Is the observation level the county or the
individual/household/family/? )
Stephen
-------------------------------------------------------------
Professor Stephen P. Jenkins <[email protected]>
Institute for Social and Economic Research
University of Essex, Colchester CO4 3SQ, U.K.
Tel: +44 1206 873374. Fax: +44 1206 873151.
http://www.iser.essex.ac.uk
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