Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: Sampling weights (pweights) and regression analysis

From   Fatih Yilmaz <>
Subject   st: Sampling weights (pweights) and regression analysis
Date   Wed, 11 Jul 2012 14:15:36 -0600

Dear Statalist, 

I am having trouble with using sampling weights in my simple regression analysis.

Here is the story: 

The survey data I have is not representative, where some groups were deliberately over or under-sampled. 
     The weights I was provided ara computed as follows:

For group one (strata), population weight is 60%
          				  sample weight is 40% 
					Final Pweight = 60%/40%=1.5 

My questions: 

1- I needed to drop some of the observations from the survey data: outliers, missings obs and also unrelated data.
     so, can I still use the old (initial) weights or do I have to re-weight the data with respect to the dropped observations? 
     Or how problematic could it be to use old weights?

2- Since, my weights were computed as w=(pop%)/(sample%) (in general, some other researchers may compute them as w=(sample%)/(pop%) ), 
when I estimate weighted OLS should I use "reg y x [pw=1/w]" or  ""reg y x [pw=w]".

Could you pls also recommend some resources on sampling weights and regression analysis (preferably practical sources ),

Thanks very much 

Fatih Yilmaz 
*   For searches and help try:

© Copyright 1996–2016 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index