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Re: st: RE: RE: Replace missing values by 0


From   Richard Goldstein <richgold@ix.netcom.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: RE: RE: Replace missing values by 0
Date   Tue, 10 Aug 2010 12:56:32 -0400

be careful -- while what you say is true, you also won't be asked if
you were happy doing "x" -- and 0 is not correct for that

I definitely agree with Tony that just mindlessly doing what the OP
asked is very dangerous

Rich

On 8/10/10 12:13 PM, David Bell wrote:
> -
> In many cases, skip patterns in questionnaires leave behind missing values, either -9's or .'s.  If you told the interviewer that you didn't do behavior X in the past year, you won't be asked how many times you did X in the past 30 days.  The missing value for 30-day behavior X really does represent a zero.
> 
> Dave
> ====================================
> David C. Bell
> Professor of Sociology
> Indiana University Purdue University Indianapolis (IUPUI)
> (317) 278-1336
> ====================================
> 
> 
> 
> 
> On Aug 9, 2010, at 6:29 PM, David Radwin wrote:
> 
>> Tony,
>>
>> Sometimes data, especially count data, are stored in a spreadsheet where a
>> blank cell indicates a zero value. For example, if the data are
>> hand-entered and there are a lot of zero values, it is more efficient not
>> to enter a zero, and many spreadsheet functions treat the blank cell as a
>> zero value.
>>
>> However, if you paste or -insheet- these data into Stata, the blank cells
>> are encoded as missing values. In this case it is necessary to convert the
>> missing values to zeroes.
>>
>> David
>>
>> --
>> David Radwin
>> Research Associate
>> MPR Associates, Inc.
>> 2150 Shattuck Ave., Suite 800
>> Berkeley, CA 94704
>> Phone: 510-849-4942
>> Fax: 510-849-0794
>>
>> www.mprinc.com
>>
>>
>>> -----Original Message-----
>>> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-
>>> statalist@hsphsun2.harvard.edu] On Behalf Of Lachenbruch, Peter
>>> Sent: Monday, August 09, 2010 2:59 PM
>>> To: 'statalist@hsphsun2.harvard.edu'
>>> Subject: st: RE: Replace missing values by 0
>>>
>>> In all of the discussion of this query, nobody has asked why it is
>>> important to do this?  If you are computing means, the 0 values will
>>> distort the mean (or median if enough), and if you simply want to ignore
>>> zeros with "if x~=0") retaining the missing value will do this
>>> automatically.
>>>
>>> I am unsure if I've ever had a reason to convert missing values to a
>>> numeric value, but have had many times when the -9 for missing (or
>>> whatever) had to be set to "."
>>>
>>> Tony
>>>
>>> Peter A. Lachenbruch
>>> Department of Public Health
>>> Oregon State University
>>> Corvallis, OR 97330
>>> Phone: 541-737-3832
>>> FAX: 541-737-4001
>>>
>>>
>>> -----Original Message-----
>>> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-
>>> statalist@hsphsun2.harvard.edu] On Behalf Of Hobst
>>> Sent: Monday, August 09, 2010 1:55 AM
>>> To: statalist@hsphsun2.harvard.edu
>>> Subject: st: Replace missing values by 0
>>>
>>> I have two variabled called "prean" and "pa_kum" that contain missing
>>> values.
>>> These missing values i would like to replace by 0 (zero). What command
>> can
>>> i
>>> use to do this?
>>>
>>> Thanks in advance for your support. Regards
>>> --
>>> View this message in context:
>>> http://statalist.1588530.n2.nabble.com/Replace-missing-values-by-0-
>>> tp5388239p5388239.html
>>> Sent from the Statalist mailing list archive at Nabble.com.
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