# RE: st: RE: Lincom after sepov

 From "Nick Cox" To Subject RE: st: RE: Lincom after sepov Date Tue, 24 Jun 2008 17:59:40 +0100

```Thanks for the correction to your previous post.

The same point applies. It is not -sepov- doing this, but whatever it calls.

Someone else -svy-savvy may be able to help with your main problem.

Nick
n.j.cox@durham.ac.uk

Joao Ricardo F. Lima

Thanks Nick,

actually, sepov store the values of FGT in e(b), not in e(V). See:

sepov renagr_nag rennag if famtipo == 1 [w=pesopes2], p(120)
strata(strat) psu(psu) ci meff
(sampling weights assumed)

Poverty measures for the variable renagr_nag: (unlabeled)

Survey mean estimation

pweight:  pesopes2                                Number of obs    =       849
Strata:   strat                                   Number of strata =        43
PSU:      psu                                     Number of PSUs   =       153
Population size  = 394883.36

------------------------------------------------------------------------------
Mean |   Estimate    Std. Err.   [95% Conf. Interval]        Meff
---------+--------------------------------------------------------------------
p0 |   .1953685    .0173466    .1609916    .2297453    1.644852
p1 |   .0671076    .0064495    .0543262     .079889    1.270128
p2 |   .0327589    .0037762    .0252754    .0402425    1.198951
------------------------------------------------------------------------------

Poverty measures for the variable rennag: (unlabeled)

Survey mean estimation

pweight:  pesopes2                                Number of obs    =       849
Strata:   strat                                   Number of strata =        43
PSU:      psu                                     Number of PSUs   =       153
Population size  = 394883.36

------------------------------------------------------------------------------
Mean |   Estimate    Std. Err.   [95% Conf. Interval]        Meff
---------+--------------------------------------------------------------------
p0 |   .0649527    .0079664    .0491652    .0807402    .9895778
p1 |   .0218262    .0033303    .0152263    .0284261    1.086596
p2 |   .0098536     .002091    .0057097    .0139976    1.136367
------------------------------------------------------------------------------

. matrix list e(b)

e(b)[1,3]
p0         p1         p2
y1   .0649527  .02182618  .00985364

I want to compare if 0.0649527 = 0.1953685 statistically, but donīt
known how to do this.

2008/6/24 Nick Cox <n.j.cox@durham.ac.uk>:
> Standard advice for this list (more usually ignored than not) is to say where user-written stuff you are using comes from.
>
> -sepov- has this source
>
> STB-51  sg117 . . Robust std errors for Foster-Greer-Thorbecke poverty indices
>        (help sepov if installed) . . . . . . . .  D. Jolliffe and A. Semykina
>        9/99    pp.34--36; STB Reprints Vol 9, pp.200--203
>        provides estimates of standard errors for the Foster-Greer-
>        Thorbecke class of poverty indices; handles complex survey
>        designs including stratification and multi-stages
>
> and evidently the authors have moved since then.
>
> A Google for Dean Jolliffe seems to yield a direct hit. I don't know Dean and have no way of knowing whether he still supports -sepov-.
>
> But the code remains accessible. -viewsource sepov.ado- and you can look at the code and have a stab at answering your own question. You will see that your statement is not quite correct. -epov- is not eclass and does not store anything in e(). Whatever e(V) you see is left over from -svymean-, or so I guess. This may help you move forward.
>
> Nick
> n.j.cox@durham.ac.uk
>
> Joao Ricardo F. Lima
>
> I'm writing because I want an advice. I'm using sepov to get FGT
> indexes for two variables. After estimation I would like to compare if
> the results are statistical different. I am trying to use "lincom",
> but unsucessfull because sepov stores in e(V) only the estimation for
> the last variable, isnīt it?
>
> I am doing this:
>
> sepov var1 var2 , p(pl) psu (psu) strat (strat) ci meff
>
> And I would like something like this
>
> lincom p0[var1] - p0[var2]
>
> How can I do this? Is there another way to test if the values of FGT
> indexes are the same?
>
> I wrote to sepov authors, but their email address change.
>
> The error that the other server returned was: 550 550 5.1.1 Mailbox
> <anastassia.semykina@cerge.cuni.cz> does not exist (state 14).
> The error that the other server returned was: 550 550 5.1.1 Mailbox
> <dean.jolliffe@cerge.cuni.cz> does not exist (state 14).

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```