re: st: analysis of complex surveys

[Steven Samuels <ssamuels@albany.edu>]

1.  To pool the results from the different surveys you may treat the  
country as another stratifying variable.  Assume that the name of the  
within-country stratification variable is
"stratum".  Then do the following:

egen superstrat=group(country stratum)

User "superstrat" as your new stratum variable.


2. To make cross-country comparisons of regression coefficients you  
may also add country indicators to the regression equation.  Then you  
may test country-variable interactions.  Alternately, you can use the  
noconstant option to fit a separate set of regression coefficients  
for each country.  Suppose you have 2 countries, 1 and 2, and your  
covariates are X and Z

form
I1  = 1   if country =1   =0 if Country = 2
X1= X                      "
Z1 = Z                     "

I2   = 1   if country=2 , =0 if country =1
X2= X                     "
Z2 =Z                     "



svy: reg y = I1 X1 Z1 I2 X2 Z2, nocons

test  X1=X2
test Y1=Y2

 etc.

Good luck!



From: ealhussainy@worldbank.org
Subject: st: analysis of complex surveys

Dear all,

I am attempting to analyze a set of complex household surveys that  
used a
standard questionnaire but were conducted in different countries  
using different
sampling methods (multistage stratification and clustering). I have  
household
weights as well as stratification and clustering information for each  
survey. My
question is two-fold:

1. Is it possible to "pool" or in some way combine data across  
surveys for a
fixed-effects regression analysis?
2. If I run regressions at the country-level, is there a way to make
cross-country comparisons using regression coefficients or marginal  
effects?

Thanks much in advance.

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