Re: st: ranking with weights

[Steven Samuels <sjhsamuels@earthlink.net>]

Cindy, What are the analytic units (people? regions?).  What are the  
"weights"? What is "expenditure"?  How is it measured.  What do you  
mean that some regions are "less sampled" than others.  It's not  
clear, for example, if this is a sample, and if so, of what? So,  
please describe the  study design in detail.  Last question: what is  
the purpose of the ranking?

-Steve

On Dec 2, 2008, at 12:54 PM, Cindy Gao wrote:

> Hello
>
> I am trying to find a way to rank weighted data (since the egen  
> function -rank- does not work with weights). A simple way would be  
> order the data in terms of variable that I have interest in  
> (monthly expenditure) and then create a new variable like -g  
> rank1=sum(weight)-. But, there is problem. Some of my observations  
> are "tied" as they have the same level of expenditure. Using the  
> simple method I mention means that some observations are ranked  
> above others even though they have same level of expenditure. This  
> is a problem as the weights are large so you find that 2  
> observations are ranked with bug gap in between even though same  
> level of expenditure. It is even bigger problem because the weights  
> might be correlated with some other variables I am interested in  
> (like region, since some regions are less sampled than other). I  
> also try multiplying the expenditure ranking by the weight, but  
> this gives wrong results (for example they do not add up to weighted
>  total). Can anyone help? In other words, I would like for all  
> observations with same expenditure to have same rank, which I  
> assume would be some average of all the weighted observations  
> having that same expenditure.  I include a sample dataset below:
>
> expenditure       weighting        rank       rank1      weighted_rank
> 10                          341            1           341           
> 341
> 12                          1065          2.5        1406         ???
> 12                          98             2.5        1504
> 15                          254            4          1758
> .......
>
> thanks,
>
> Cindy
>
>
>
>
>
>
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