Re: st: Selecting a sample to compromise between significant size and geographical dispersion

[Partho Sarkar <partho.ss+lists@gmail.com>]

Thanks for the prompt response Marten!  So there IS a trade-off it
seems, right?  If I set a certain cut-ff level of market size, I get a
certain geographical pattern.  What I want is a way to visualise this
relationship- e.g., a table or graph that would show the pairs of
cut-off size versus a dispersion "index" , so that I could then choose
the "optimal" (subjectively) cut-off.  Or doesn't this make sense?  By
the way, I wonder if this could be handled through Stata's Survey
commands, which I have never gone into.

Thanks again.

Partho

On Thu, Sep 15, 2011 at 1:36 PM, Maarten Buis <maartenlbuis@gmail.com> wrote:
> What is the population that you want to generalize to? My suspicion is
> that as soon as you have defined that, you'll see that there is no
> trade-off. For example: if the population of interest is markets with
> more than median trading volume than the geographic dispersion is
> given by that constraint. Having two conflicting criteria suggests to
> me that your definition of the population is still too fuzzy.
>
>
> Hope this helps,
> Maarten
>
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