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RE: st: Creating a dummy variable under certain conditions


From   sebas nicaise <sebasnicaise@hotmail.com>
To   <statalist@hsphsun2.harvard.edu>
Subject   RE: st: Creating a dummy variable under certain conditions
Date   Mon, 4 Jun 2012 08:22:13 +0000

Dear Abhimanyu,

First of all I am pleased with your quick responses and thoughts.
However, The code still does not work :)
When I enter : bys gvkey: gen new_viol_dummy=L.viol+L2.viol+L3.viol+L4.viol==0
tspell new_viol_dummy
replace new_viol_dummy=0 if ceil(_seq/5)!=floor(_seq/5) & _seq!=1

I get: 
date gvkey viol new_viol_dummy
1997q1 1004 0 0
1997q2 1004 0 0
1997q3 1004 0 0
1997q4 1004 0 0
1998q1 1004 0 1
1998q2 1004 0 0
1998q3 1004 0 0
1998q4 1004 0 0
1999q1 1004 0 1
1999q2 1004 0 0

It is important that new viol dummy can only be 1 if viol is 1 and in the previous 4 quarters viol is 0.

> Date: Sun, 3 Jun 2012 22:09:08 +0200
> Subject: Re: st: Creating a dummy variable under certain conditions
> From: abhimanyu.arora1987@gmail.com
> To: statalist@hsphsun2.harvard.edu
> 
> Hi Sebas
> On further thoughts this is an improvement again using Nick's
> -tsspell- downloadable from SSC
> 
> bys gvkey: gen new_viol_dummy=L.viol+L2.viol+L3.viol+L4.viol==0
> tspell new_viol_dummy
> replace new_viol_dummy=0 if ceil(_seq/5)!=floor(_seq/5) & _seq!=1
> 
> Cheers
> 
> Abhimanyu
> 
> On Sun, Jun 3, 2012 at 9:37 PM, Abhimanyu Arora
> <abhimanyu.arora1987@gmail.com> wrote:
> > I think this should solve Sebas' problem
> >
> > bys gvkey: gen new_viol_dummy=L.viol+L2.viol+L3.viol+L4.viol==0
> >
> > After this Nick's -tsspell- (from SSC) can come to the rescue
> >
> > tspell new_viol_dummy
> >
> > bys gvkey:replace new_viol_dummy=0 if inrange(_seq,2,4)
> >
> >
> >
> > On Sun, Jun 3, 2012 at 9:06 PM, Nick Cox <njcoxstata@gmail.com> wrote:
> >> It makes no sense to work with L.gvkey as this just means the previous
> >> panel identifier, which is constant within a panel . This has already
> >> been pointed out earlier in the thread. Referring to L.gvkey was a
> >> slip that was quickly corrected.
> >>
> >> Nick
> >>
> >> On Sun, Jun 3, 2012 at 7:59 PM, sebas nicaise <sebasnicaise@hotmail.com> wrote:
> >>> Still not working :(
> >>>
> >>>
> >>>
> >>> When I use this :
> >>>
> >>> bys gvkey gen new_viol_dummy=L.gvkey+L2.gvkey+L3.gvkey+L4.gvkey==0
> >>>
> >>>
> >>> bys gvkey:replace new_viol_dummy=0 if new_viol_dummy[_n-1]==1
> >>>
> >>>
> >>> I get this:
> >>>
> >>> date gvkey viol new_viol_dummy
> >>> 1997q1 1004 0 0
> >>> 1997q2 1004 0 0
> >>> 1997q3 1004 0 0
> >>> 1997q4 1004 0 0
> >>> 1998q1 1004 0 1
> >>> 1998q2 1004 0 0
> >>> 1998q3 1004 0 1
> >>> 1998q4 1004 0 0
> >>> 1999q1 1004 0 1
> >>> 1999q2 1004 0 0
> >>> 1999q3 1004 0 1
> >>> 1999q4 1004 0 0
> >>> 2000q1 1004 0 1
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Could you have another look at it :)?
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>> Date: Sun, 3 Jun 2012 20:24:33 +0200
> >>>> Subject: Re: st: Creating a dummy variable under certain conditions
> >>>> From: abhimanyu.arora1987@gmail.com
> >>>> To: statalist@hsphsun2.harvard.edu
> >>>>
> >>>> Now I see, you have an additional condition, Sebastian.
> >>>>
> >>>> In that case, you could simply add an additional command in addition
> >>>> to either Nick's or my solution with L. (not the F. one)
> >>>> -bys gvkey:replace new_viol_dummy=0 if new_viol_dummy[_n-1]==1
> >>>>
> >>>>
> >>>> date gvkey viol new_viol_dummy
> >>>> 1997q1 1004 0 0
> >>>> 1997q2 1004 0 0
> >>>> 1997q3 1004 0 0
> >>>> 1997q4 1004 0 0
> >>>> 1998q1 1004 0 0
> >>>> 1998q2 1004 0 0
> >>>> 1997q1 1021 0 0
> >>>> 1997q2 1021 0 0
> >>>> 1997q3 1021 0 0
> >>>> 1997q4 1021 0 0
> >>>> 1998q1 1021 0 0
> >>>> 1998q2 1021 0 0
> >>>> 1998q3 1021 0 0
> >>>> 1998q4 1021 1 1
> >>>> 1999q1 1021 1 0
> >>>> 1999q2 1021 1 0
> >>>> 1999q3 1021 1 0
> >>>> 1999q4 1021 0 0
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> On Sun, Jun 3, 2012 at 7:46 PM, sebas nicaise <sebasnicaise@hotmail.com> wrote:
> >>>>> Dear Abhimanyu,
> >>>>>
> >>>>> This also does not give me the right answer.It gives:
> >>>>>
> >>>>> date gvkey viol new_viol_dummy1998q4 1095 0 01999q1 1095 0 01999q2 1095 0 01999q3 1095 0 01999q4 1095 1 02000q1 1095 0 02000q2 1095 1 12000q3 1095 1 12000q4 1095 1 12001q1 1095 1 12001q2 1095 1 12001q3 1095 1 0
> >>>>>
> >>>>> It should be:000010000000
> >>>>>
> >>>>> I think the command should be more complicated since the new viol dummy variable is only 1 under certain strict conditions.NEWVIOL is only 1 if the VIOL dummy of the corresponding GVKEY has a 1 IF in the four previous quarters a 0. Furthermore, if NEWVIOL documents a 1, it can only be a 1 again after four quarters of 0.
> >>>>>
> >>>>> Hope you, or someone else, can help me with this seemingly easy task :)
> >>>>>
> >>>>> Thank you,Sebastiaan
> >>>>> ----------------------------------------
> >>>>>> Date: Sat, 2 Jun 2012 17:21:54 +0200
> >>>>>> Subject: Re: st: Creating a dummy variable under certain conditions
> >>>>>> From: abhimanyu.arora1987@gmail.com
> >>>>>> To: statalist@hsphsun2.harvard.edu
> >>>>>>
> >>>>>> Okay, if I infer correctly, try this: bys gvkey: gen
> >>>>>> new_viol_dummy=viol+F1.viol+F2.viol+F3.viol==4.
> >>>>>> Seems good?
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> On Sat, Jun 2, 2012 at 5:07 PM, sebas nicaise <sebasnicaise@hotmail.com> wrote:
> >>>>>>> Maybe I can better show it visually:
> >>>>>>> Your commands give me the following output:
> >>>>>>> bys gvkey: gen new_viol_dummy=L.viol+L2.viol+L3.viol+L4.viol==0
> >>>>>>> date gvkey viol new_viol_dummy 1997q1 1004 0 01997q2 1004 0 01997q3 1004 0 01997q4 1004 0 01998q1 1004 0 11998q2 1004 0 11997q1 1021 0 01997q2 1021 0 01997q3 1021 0 01997q4 1021 0 01998q1 1021 0 11998q2 1021 0 11998q3 1021 0 11998q4 1021 1 11999q1 1021 1 01999q2 1021 1 01999q3 1021 1 01999q4 1021 0 0
> >>>>>>> While I want this: date gvkey viol new_viol_dummy 1997q1 1004 0 01997q2 1004 0 01997q3 1004 0 01997q4 1004 0 01998q1 1004 0 01998q2 1004 0 01997q1 1021 0 01997q2 1021 0 01997q3 1021 0 01997q4 1021 0 01998q1 1021 0 01998q2 1021 0 01998q3 1021 0 01998q4 1021 1 11999q1 1021 1 01999q2 1021 1 01999q3 1021 1 01999q4 1021 0 0
> >>>>>>> If it is not clear what I mean, let me know :)
> >>>>>>> Thank you,Sebastiaan
> >>>>>>>> Date: Sat, 2 Jun 2012 16:34:41 +0200
> >>>>>>>> Subject: Re: st: Creating a dummy variable under certain conditions
> >>>>>>>> From: abhimanyu.arora1987@gmail.com
> >>>>>>>> To: statalist@hsphsun2.harvard.edu
> >>>>>>>>
> >>>>>>>> Sebas,
> >>>>>>>> Adding to Nick's comment, did you not -xtset- the data? You also have
> >>>>>>>> an option of bys id_var: command, otherwise
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> On Sat, Jun 2, 2012 at 4:29 PM, Nick Cox <njcoxstata@gmail.com> wrote:
> >>>>>>>>> You will probably want to exclude or ignore the first few observations
> >>>>>>>>> in each panel or -replace- it with missing. Otherwise, what's wrong?
> >>>>>>>>>
> >>>>>>>>> Abhimanyu's slip has already been corrected in this thread, as below.
> >>>>>>>>>
> >>>>>>>>> Nick
> >>>>>>>>>
> >>>>>>>>> On Sat, Jun 2, 2012 at 3:12 PM, sebas nicaise <sebasnicaise@hotmail.com> wrote:
> >>>>>>>>>
> >>>>>>>>>> Thank you for the quick replys.
> >>>>>>>>>>
> >>>>>>>>>> However, the suggested solutions did not give the right answer.
> >>>>>>>>>>
> >>>>>>>>>> Nick, your solution gives me way too many 1's. I do think the first step with the cusum was the right way to go.
> >>>>>>>>>>
> >>>>>>>>>> Abhimanyu, your solution does not distinquish between the id's, the calculation has to start over for every gvkey.
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> Hope you can have another look at it, I will also try to work with the suggestions you gave me.
> >>>>>>>>>>
> >>>>>>>>>>> From: abhimanyu.arora1987@gmail.com
> >>>>>>>>>>> To: statalist@hsphsun2.harvard.edu
> >>>>>>>>>>>
> >>>>>>>>>>> Thanks Nick, yes.
> >>>>>>>>>>> But I would go for your solution which would be better in case he had
> >>>>>>>>>>> a longer lag.
> >>>>>>>>>>>
> >>>>>>>>>>> On Sat, Jun 2, 2012 at 2:56 PM, Nick Cox <njcoxstata@gmail.com> wrote:
> >>>>>>>>>>>> This looks OK as long as you substitute -viol- for -gvkey-. The
> >>>>>>>>>>>> previous values concerned are for -viol-, not -gvkey-.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Nick
> >>>>>>>>>>>>
> >>>>>>>>>>>> On Sat, Jun 2, 2012 at 1:51 PM, Abhimanyu Arora
> >>>>>>>>>>>> <abhimanyu.arora1987@gmail.com> wrote:
> >>>>>>>>>>>>
> >>>>>>>>>>>>> Try this if your data is -xtset-ted
> >>>>>>>>>>>>> gen new_viol_dummy=L.gvkey+L2.gvkey+L3.gvkey+L4.gvkey==0
> >>>>>>>>>>>>
> >>>>>>>>>>>>> On Sat, Jun 2, 2012 at 2:06 PM, sebas nicaise <sebasnicaise@hotmail.com>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>> I am struggeling with creating a new dummy variable. I have a very large
> >>>>>>>>>>>>>> (unbalanced) panel dataset that looks like this:
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> date gvkey viol
> >>>>>>>>>>>>>> 1997q1 1021 0
> >>>>>>>>>>>>>> 1997q2 1021 0
> >>>>>>>>>>>>>> 1997q3 1021 0
> >>>>>>>>>>>>>> 1997q4 1021 0
> >>>>>>>>>>>>>> 1998q1 1021 1
> >>>>>>>>>>>>>> 1998q2 1021 0
> >>>>>>>>>>>>>> 1998q3 1021 0
> >>>>>>>>>>>>>> 1998q4 1021 1
> >>>>>>>>>>>>>> 1999q1 1021 0
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> 1999q2 1021 0
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> 1999q3 1021 0
> >>>>>>>>>>>>>> 1999q2 1023 0
> >>>>>>>>>>>>>> 1999q3 1023 1
> >>>>>>>>>>>>>> 1999q4 1023 0
> >>>>>>>>>>>>>> 2000q1 1023 0
> >>>>>>>>>>>>>> 2000q2 1023 1
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> Where date is calender quarter, gvkey is the company identifier and viol a
> >>>>>>>>>>>>>> dummy which equals 1 if the firm is in violation of a covenant in a private
> >>>>>>>>>>>>>> debt contract.
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> The problem is that I have to create a new dummy variable ( new violation)
> >>>>>>>>>>>>>> which meets certain conditions.
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> The new violation dummy is only allowed to be 1 if in the previous 4
> >>>>>>>>>>>>>> quarters of a certain company (gvkey) is 0.
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> This means for example that:
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> date gvkey viol Newviolation
> >>>>>>>>>>>>>> 1997q1 1021 0 0
> >>>>>>>>>>>>>> 1997q2 1021 0 0
> >>>>>>>>>>>>>> 1997q3 1021 0 0
> >>>>>>>>>>>>>> 1997q4 1021 0 0
> >>>>>>>>>>>>>> 1998q1 1021 1 1
> >>>>>>>>>>>>>> 1998q2 1021 0 0
> >>>>>>>>>>>>>> 1998q3 1021 0 0
> >>>>>>>>>>>>>> 1998q4 1021 1 0
> >>>>>>>>>>>>>> 1999q1 1021 0 0
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> 1999q2 1021 0 0
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> 1999q3 1021 0 0
> >>>>>>>>>>>>>> 1999q2 1023 0 0
> >>>>>>>>>>>>>> 1999q3 1023 1 0
> >>>>>>>>>>>>>> 1999q4 1023 0 0
> >>>>>>>>>>>>>> 2000q1 1023 0 0
> >>>>>>>>>>>>>> 2000q2 1023 1 0
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> I do not know how to tell Stata to create this variable, Hope someone is
> >>>>>>>>>>>>>> so kind to help me.
> >>>>>>>>>>>>
> >>>>>>>>>>>> *
> >>>>>>>>>>>> * For searches and help try:
> >>>>>>>>>>>> * http://www.stata.com/help.cgi?search
> >>>>>>>>>>>> * http://www.stata.com/support/statalist/faq
> >>>>>>>>>>>> * http://www.ats.ucla.edu/stat/stata/
> >>>>>>>>>>>
> >>>>>>>>>>> *
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> >>>>>>>>>
> >>>>>>>>> *
> >>>>>>>>> * For searches and help try:
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> >>>>>>
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> >>>>>
> >>>>> *
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> >>>>
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> >>
> >> *
> >> * For searches and help try:
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> 
> *
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