[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]
Re: st: Survey analysis: Why does PSU affect proportions?
Your number of obs changed when including PSU/stratum vars.
Try -codebook psu strat- to see # of missing values, etc.
On 7/10/06, Craig Anderson <email@example.com> wrote:
I am using a published dataset (from CDC) and I want to verify that I
can duplicate the published results before I begin my analysis. I
found that including clustering and stratification variables changed
proportions, not only standard errors. In the output that follows, I
first used only the weights. This gives results that agree with the
published estimates of the proportions (produced using SUDAAN). Next
I used the PSU and STRATA, and get different proportions, but
confidence intervals that agree with the published results, with
minor variations in other runs. I don't think the clustering by
strata and psu should influence proportions, only their variance.
* For searches and help try: