RE: st: Differencing problem

[Michael Betz <betz.40@buckeyemail.osu.edu>]

. d college_

              storage  display     value
variable name   type   format      label      variable label
------------------------------------------------------------------------------------------------------------------------------------
college_        float  %9.0g                  

. su college_

    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
    college_ |       716    94970.41    257294.9       3479    3707827

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
Sent: Wednesday, June 26, 2013 6:53 PM
To: statalist@hsphsun2.harvard.edu
Subject: Re: st: Differencing problem

I would bet No. Show us the results of

d var
su var

Nick
njcoxstata@gmail.com

On 26 June 2013 23:38, Michael Betz <betz.40@buckeyemail.osu.edu> wrote:

> The code you sent works fine. I am using -xtset- to define the panel data. Will that make a difference?

Sergiy Radyakin

> See if this works. The problem may be with the time variable. Sergiy
>
> sysuse auto,clear
> generate t=_n
> tsset t
> generate x=d.mpg
> list mpg x

On Wed, Jun 26, 2013 at 4:20 PM, Michael Betz <betz.40@buckeyemail.osu.edu> wrote:

>> I am trying to use the "d." operator to get differenced observations 
>> but am having some trouble. When I try to calculate differenced 
>> observations using
>>
>> gen newvar=d.(var)
>>
>> Stata returns each observation as missing. My data has observations for each variable in each of two time periods and variation exists over the two time periods. I've used the "d." before without problems so I'm not sure what I'm missing here. Any help is appreciated.

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