Re: st: svy: total command

[Rebecca Pietrelli <rebecca.pietrelli@gmail.com>]

Dear Steve,

first of all, I am very sorry.
My question was inaccurate and I know that time is precious!

The survey I am using collects information on households residing in Uganda.

Sampling design:
A two-stage stratified sample design was adopted. First stage:
Selection of  Enumeration Areas (ea), proportionally done on the basis
of the number of households according to Uganda Household Survey. Also
the selection was done separately for urban and rural  areas. Second
stage: systematic sampling procedure was adopted in order to select
(in each ea) 4 households with an international migrant, 3 households
with one or more internal migrant and 3 with no migrants.

In one data file, for each household, the list of household members
living outside the household is reported, with all the information
about each migrant, including remittances behaviour.
In the second data file, for each household, the list of non-household
members who remit to the household is reported, with all the
information about each migrant.

The aim of my analysis it to compute the total amount of remitters
(and remittances), both former household members and non-household
members (namely household members and friends), distinguishing
internal and international remitters.


I used the following commands in both data files.

. svyset earea [pw=hhweight], strata(stratum)

      pweight: hhweight
          VCE: linearized
  Single unit: missing
     Strata 1: stratum
         SU 1: earea
        FPC 1: <zero>

I have generated a dummy variable, labelled internal, = 1 if the
migrant has migrated within Uganda and = 0 if the migrant has migrated
out of Uganda.
Also I have generated a dummy variable, labelled dremit1, = 1  if the
migrant remits and zero otherwhise.

I used the following command to compute the total number of remitters
in each data files (hh members and friends), distinguishing internal
(1) and international(0):

First file: former household members:

. svy, over(internal): total dremit1
(running total on estimation sample)

Survey: Total estimation

Number of strata =       2         Number of obs    =     1645
Number of PSUs   =     191         Population size  =  4942119
                                   Design df        =      189

            0: internal = 0
            1: internal = 1

--------------------------------------------------------------
             |             Linearized
        Over |      Total   Std. Err.     [95% Conf. Interval]
-------------+------------------------------------------------
dremit1      |
           0 |   233898.1   29978.48      174762.7    293033.5
           1 |    1064315   131143.6      805622.1     1323009
--------------------------------------------------------------

Second file: Non-household members:

. svy, over(internal): total dremit1
(running total on estimation sample)

Survey: Total estimation

Number of strata =       2          Number of obs    =     217
Number of PSUs   =      90          Population size  =  564846
                                    Design df        =      88

            0: internal = 0
            1: internal = 1

--------------------------------------------------------------
             |             Linearized
        Over |      Total   Std. Err.     [95% Conf. Interval]
-------------+------------------------------------------------
dremit1      |
           0 |   101800.5   22591.33         56905      146696
           1 |   324690.8   66555.15      192426.4    456955.2
--------------------------------------------------------------

Finally, I think to sum the total numbers of remitters (household
members and non-household members), separating internal and
international migrants. In other words, the results obtained from the
two tables above.
Also I have applied the same procedure to compute the total amount of
remittances.

Is this procedure (working on two data files) correct?

The weights are at household level and I am computing the total number
of remitters. Is there a problem of bias, like here? If yes, How can I
solve it?

http://www.stata.com/statalist/archive/2010-09/msg00445.html

Thank you and sorry again!

Rebecca








2012/11/20 Steve Samuels <sjsamuels@gmail.com>:
> There's no such thing in Stata as a "label variable". I'm guessing that
> you refer to a variable with values 1 = "Yes" 2 = "No". that has been
> assigned a "value label" the name of which you can find with "des
> q518_1" In that case, -total dremit1- is correct. If there are other
> numbered responses that you con't want to count as "No", (e.g. 8=
> "Refused", 9="Not Applicable"), you might have to restrict to "Yes" and
> "No", e.g.
>
> ************************
> svy, subpop(if inlist(q518_1,1,2) over(internal): total dremit1
>  ************************
>
> But _if_ q518_1 is coded just as "internal" is coded, then
> generating  dremit1 was unnecessary.
>
>
> When you joined Statalist you you received a welcome email that stated:
> "Please read that FAQ at your convenience, but certainly before you post
> anything to the list."
>
> I would not have guess what your variables are if you had followed
> Statalist FAQ Section 3.3, first sentence: "Say exactly what you typed
> and exactly what Stata typed (or did) in response. N.B. exactly!".
> If you had yourself compared the results of the two -total- statements,
> the answer to your question might have been obvious, making a post
> unnecessary.
>
> Steve
>
>
> On Nov 19, 2012, at 5:49 AM, Rebecca Pietrelli wrote:
>
> Dear all,
>
> I am using the Stata command svy: total, in order to estimate the
> total number of migrants from Uganda, residing within or outside
> Uganda, who remit money to their origin family.
>
>
> The specific command I am using is:
>
> . tab q518_1, gen(dremit)
>
> (the answer to the question 5.18_1 is a label variable: yes if the
> migrant remits and no otherwhise)
>
> . svy, over(internal): total dremit1
>
> (internal = 1 if the migrant has migrated within Uganda and 0 otherwhise).
>
>
> Is this procedure correct?
> Or should I use total command directly on label variable q518_1?
>
> thank you
> Rebecca
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