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Re: st: Creating a dummy variable under certain conditions


From   Abhimanyu Arora <abhimanyu.arora1987@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Creating a dummy variable under certain conditions
Date   Sun, 3 Jun 2012 21:37:18 +0200

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/
>>>>>>>>>>
>>>>>>>>>> *
>>>>>>>>>> * 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/
>>>>>>>>> *
>>>>>>>>> * 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/
>>>>>>>>
>>>>>>>> *
>>>>>>>> * 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/
>>>>>>>
>>>>>>> *
>>>>>>> * 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/
>>>>>>
>>>>>> *
>>>>>> * 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/
>>>>>
>>>>> *
>>>>> * 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/
>>>>
>>>> *
>>>> * 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/
>>>
>>> *
>>> * 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/
>> *
>> *   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/
>
> *
> *   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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