13 Feb
2003
13 Feb
'03
6:27 p.m.
below...
On Thu, 13 Feb 2003, SUAZO-GARCIA, BELKIS wrote:
Dear Professor Gary King:
I am using your AMELIA program for a sample drawn from NELS:88 (National
Education Longitudinal Study of 1988, administered by the U.S. Department of
Education, National Center of Education Statistics). The NELS:88 is based
on a two stage, stratified sample design, with schools as the first-stage
unit and students within schools as the second-stage unit. Because of the
sampling design, I must use a statistical program that calculates standard
errors by taking into account the complex sample design. So, I can't use
STATA because it does not correct for complex sample designs. Instead, I am
using AM, a program designed by the American Institutes for Research
(http://am.air.org).
I want to create one file in SPSS that contains all five Ameliarized data
sets. I plan to bring this one file into AM and divide the sample weight by
five to adjust the degrees of freedom to the correct sample size. I will
like to know if this a correct use of the Ameliarized data sets. Is this
procedure similar to what happens to the data in STATA? The alternative is
to run my models separately on each Ameliarized data set and then average
the results myself. I prefer not to do the latter because it will be an
enormous task.
Thank you for your assistance. I look forward to your response.
Sincerely,
Belkis Suazo-Garcia
________________________________________________
Belkis Suazo-Garcia,
Doctoral Candidate
Ph.D. Program in Sociology
CUNY Graduate Center
365 Fifth Avenue
New York, NY 10016
Office: (212) 817-8786
Email: bsuazo-garcia(a)gc.cuny.edu
Stata does have options to correct for complex sample designs, and so you
might want to start there. Then you could use Clarify or our MI program
to automate the combination of the data sets.
As to your question, I wouldn't stack the datasets, if that's what you
have in mind. instead, if it is too big a job to run the whole analysis 5
times, I would just use one data set, or possibly use the EM option in
Amelia and do the same. The cost would be that your standard errors would
be too small, but the point estimates would still be about right.
You should also check with Mitch Duneier in your department; he's an
expert in Amelia.
Gary King
: Gary King, King(a)Harvard.Edu http://GKing.Harvard.Edu :
: Center for Basic Research Direct (617) 495-2027 :
: in the Social Sciences Assistant (617) 495-9271 :
: 34 Kirkland Street, Rm. 2 HU-MIT DC (617) 495-4734 :
: Harvard U, Cambridge, MA 02138 eFax (928) 832-7022 :