# st: Cluster sampling help

 From Mason Sanchez To statalist@hsphsun2.harvard.edu Subject st: Cluster sampling help Date Fri, 17 Sep 2004 06:50:01 -0700 (PDT)

```Hi
For a multistage cluster sampling, I need to randomly
select clusters based on probability proportional to
size in STATA. Hypothetically, if I want to select 3
clusters randomly out of a total 5 with each cluster
having following number of households: Cluster-1 500
households, Cluster-2 1000 households, Cluster-3 1500
households, Cluster-4 2000 households and Cluster-5
3000 households. Hence total number of households is
8000. I was advised that for each cluster I first need
to calculate weight by dividing households in cluster
with total number of households, so that for cluster-1
weight would be 500/8000 = 0.0625.

Another advise i recieved was that let the number of
households in clusters be the composite size measures.
And i won't need to calculate the proportion of the
total as STATA should that for me.

I would be very grateful if someone could help me as
to how after calculating weights for each cluster I
may randomly select say 3 clusters out of total 5,
based on probability proportional to size in STATA.

Thanks indeed…

Mason

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