st: Re: Replacing Missing Values for multiple variables at one time?

["Michael Blasnik" <michael.blasnik@verizon.net>]

You can do this with a loop.  You need to be able to refer to all of the 
price variables, either by creating a list or using wildcards if the names 
are amenable.  For example, if all of your price variable names end in 
"price", then you could:

foreach pricevar of varlist *price {
cap drop avg
by village rd: egen avg=mean(`pricevar')
replace `pricevar'=avg if `pricevar'==.
}
drop avg

This will use a single varible, called avg, that will be filled in with the 
village averages you want for each of the price vars in turn.

Michael Blasnik
michael.blasnik@verizon.net

----- Original Message ----- 
From: "JEFFREY ROSEN" <rosen.53@osu.edu>
To: <statalist@hsphsun2.harvard.edu>
Sent: Saturday, July 08, 2006 5:46 PM
Subject: st: Replacing Missing Values for multiple variables at one time?



> I'm working with a dataset that is sorted by households villages and 
> rounds. The dataset is set up such that if a household made a purchase, a 
> quantity and price was inputed. If there were no purchases, a missing 
> value for price would be inputed. I would like to have the missing value 
> be replaced with an average price from each village in each round.
>
> So my dataset looks something like
>
> hhold  village   rd   1price  2price 3price
> 1      1         1    5       .      3
> 1      1         2    3       2      4
> 2      1         1    .       3      4
> 2      1         2    1       3      .
> 3      2         1    3       2      4
> 3      2         2    2       3      .
> 4      2         1    4       5      2
> 4      2         2    .       .      2
>
> What I've done in the the past if there was run:
>
> bysort village rd: egen 1pricevil = mean(1price)
> replace 1price = 1pricevil if 1price == . & 1pricevil > 0
>
> This is an easy code when I only have a couple prices, but I am working 
> with a dataset that has over 50 variables that need to be changed. Is 
> there some way to code it without having to enter in the above code for 
> every variable?
>
> Thanks in advance,
>
> Jeff Rosen
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