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From |
Nick Cox <njcoxstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Creating a dummy variable under certain conditions |

Date |
Sun, 3 Jun 2012 20:06:45 +0100 |

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/

**Follow-Ups**:**Re: st: Creating a dummy variable under certain conditions***From:*Abhimanyu Arora <abhimanyu.arora1987@gmail.com>

**References**:**st: Creating a dummy variable under certain conditions***From:*sebas nicaise <sebasnicaise@hotmail.com>

**Fwd: st: Creating a dummy variable under certain conditions***From:*Abhimanyu Arora <abhimanyu.arora1987@gmail.com>

**Re: st: Creating a dummy variable under certain conditions***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Creating a dummy variable under certain conditions***From:*Abhimanyu Arora <abhimanyu.arora1987@gmail.com>

**RE: st: Creating a dummy variable under certain conditions***From:*sebas nicaise <sebasnicaise@hotmail.com>

**Re: st: Creating a dummy variable under certain conditions***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Creating a dummy variable under certain conditions***From:*Abhimanyu Arora <abhimanyu.arora1987@gmail.com>

**RE: st: Creating a dummy variable under certain conditions***From:*sebas nicaise <sebasnicaise@hotmail.com>

**Re: st: Creating a dummy variable under certain conditions***From:*Abhimanyu Arora <abhimanyu.arora1987@gmail.com>

**RE: st: Creating a dummy variable under certain conditions***From:*sebas nicaise <sebasnicaise@hotmail.com>

**Re: st: Creating a dummy variable under certain conditions***From:*Abhimanyu Arora <abhimanyu.arora1987@gmail.com>

**RE: st: Creating a dummy variable under certain conditions***From:*sebas nicaise <sebasnicaise@hotmail.com>

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