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| From | Torsten Häberle <haeberle.torsten@gmail.com> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: Assign fiscal year-end values to a specific event in time |
| Date | Tue, 28 Jan 2014 15:47:58 +0100 |
Hi Nick, thanks for your answer. It's not an interpolation problem. I just want to assign either the last available fiscal year-end value (before the event) or the first available fiscal year-end value (after the event) to the event date. But as you said, Stata keeps on going until it reaches the next non-missing. But this is wrong in my case. Values are only valid in this time window: - Either 12 months before the event (as in dataset 1) or - 12 months after the event (as in dataset 2) But Stata should not copy a value further in the future if let's say the next fiscal year-end value is missing. I just need an approximate value on event date. For dataset 1, this is a value from the previous 12 months. For dataset 2, it is one from the following 12 months. Do you know what I mean? Thanks for helping 2014-01-28 Nick Cox <njcoxstata@gmail.com>: > Yes; if you copy previous values to replace missing values, Stata > keeps on going until it reaches the next non-missing. > > But what are you trying to do here? Like many others, your problem > seems more of an interpolation problem, and copying the last known > value is not necessarily the best way forward. See > > http://www.stata.com/statalist/archive/2014-01/msg00315.html > > for some general comments and mentions of Stata commands for interpolation. > > Nick > njcoxstata@gmail.com > > On 27 January 2014 21:36, miriam geringer <miriam.geringer@gmail.com> wrote: > >> In terms of my example: >> >> Company Date Year Price Event Month* >> A 31Okt 1988 334 >> A 29Nov 1988 10 335 >> A 31Dez 1988 336 >> A 31Jan 1989 337 >> A 14Feb 1989 EventX 338 >> A 28Feb 1989 339 >> A 31Mar 1989 340 >> B >> B >> .... >> >> *Month = Numerical date variable, monthly frequency. Stata command = mofd(Date) >> >> This is my command: bysort Company (Month): replace Price = >> Price[_n-1] if missing(Price) >> >>>>> then 10 is spread forward until the next fiscal year-end value is available >>>>> Basically, the price indicates that the fiscal year ends. In our case, on 29Nov 1988, there is a price available. This means the fiscal year ends here. And this price shall now be spread forward until the next fiscal year-end arrives. >>>>> What I wonder now: What happens if the next fiscal year-end value (in our example 1989) is now missing? >> >> Example: >> >> Company Date Year Price Event Month* >> A 31Okt 1988 334 >> A 29Nov 1988 10 335 >> A 31Dez 1988 10 336 >> A 31Jan 1989 10 337 >> A 14Feb 1989 10 EventX 338 >> A 28Feb 1989 10 339 >> A 31Mar 1989 10 340 >> A 30Apr 1989 10 >> A 31May 1989 10 >> A 30Jun 1989 10 >> A 31Jul 1989 10 >> A 31Aug 1989 10 >> A 30Sep 1989 10 >> A 31Okt 1989 . >> >> If the price on 31 Okt 1989 (the fiscal year-end) is missing, Stata >> should NOT replace the missing value with the price (10) from the >> previous fiscal year 1988. Instead, it should remain missing. But I >> think my command doesn't consider this? > > 2014-01-26 Nick Cox <njcoxstata@gmail.com>: > >>> That does not help me in terms of your example or explanation. >>> >>> A strategy is to "spread" values to other observations for the same >>> firm and then look for intersections. My Stata Journal article just >>> cited gives examples. > > On 26 January 2014 11:51, miriam geringer <miriam.geringer@gmail.com> wrote: > >>>> I have two variables, which tell me when the fiscal year ends. >>>> An exact variable, e.g. 31Jul 1994 and a year variable, e.g. 1994. > > 2014-01-26 Nick Cox <njcoxstata@gmail.com>: > >>>>> How can you tell Stata in terms of these data when fiscal years end? >>>>> >>>>> What kind of variable is -Date- (numeric or string)? Are you using >>>>> Stata dates (see -help dates and times-)? >>>>> >>>>> There is much discussion of technique in >>>>> http://www.stata-journal.com/article.html?article=dm0055 > > On 25 January 2014 19:19, miriam geringer <miriam.geringer@gmail.com> wrote: > >>>>>> I have the following two datasets: >>>>>> >>>>>> 1) >>>>>> >>>>>> Company Date Year Price Event >>>>>> A 31Okt 1988 >>>>>> A 29Nov 1988 10 >>>>>> A 31Dez 1988 >>>>>> A 31Jan 1989 >>>>>> A 14Feb 1989 EventX >>>>>> A 28Feb 1989 >>>>>> A 31Mar 1989 >>>>>> B >>>>>> B >>>>>> .... >>>>>> >>>>>> Basically, there is some event going on in 1989. This event can happen >>>>>> in every month, on every day. I want to assign a specific value from >>>>>> the previous fiscal-year to the event in 1989. To be more precise, I >>>>>> want to assign the fiscal year-end price from fiscal year 1988 to the >>>>>> event which happens - in our example - on 14Feb 1989. In the end, I >>>>>> only need to know in what year the event happened and the >>>>>> corresponding price from the previous fiscal year-end. Sometimes, >>>>>> there is no price available in the previous fiscal year, then it >>>>>> should be just marked as missing value. >>>>>> >>>>>> ---- Fiscal Year-End 1988 ------- Event -------- Fiscal Year-End 1889 >>>>>>>>>>> Assign Fiscal Year-End 1988 to Event >>>>>> >>>>>> The fiscal year can end in every month and it is possible that, for >>>>>> example, the fiscal year ends on 31Jan 1989 and the event occurs on >>>>>> 14Feb 1989. Then the 31Jan 1989 value shall be assigned. >>>>>> >>>>>> It should be something like: >>>>>> If Stata finds an EventX in fiscal year 1989 of Company A, go to >>>>>> fiscal year 1988 and take the 1988 fiscal year-end price of Company A >>>>>> and assign it to the EventX in 1989. >>>>>> >>>>>> 2) The second dataset is identical. However, this time I want to >>>>>> assign the first available fiscal year-end value. >>>>>> >>>>>> Company Date Year Price Event >>>>>> A 31Okt 1988 >>>>>> A 29Nov 1988 >>>>>> A 31Dez 1988 >>>>>> A 31Jan 1989 >>>>>> A 14Feb 1989 EventY >>>>>> A 28Feb 1989 >>>>>> A 31Mar 1989 10 >>>>>> B >>>>>> B >>>>>> .... >>>>>> >>>>>> In this example, let's assume the year ends on 31Mar 1989 and on that >>>>>> date, the price is 10 (the fiscal year-end price). I want to assign >>>>>> this price to the row with the EventY and 14Feb. The same as in >>>>>> dataset 1, just the other way around. >>>>>> >>>>>> It should be something like: >>>>>> If Stata finds an EventY in year 1989 of Company A, take the first >>>>>> available fiscal year-end value (first one available after the event >>>>>> occured). The event can occur in February and the fiscal year can >>>>>> could end shortly after. Just take the next available value, no matter >>>>>> whether there is a calendar year shift in between or not. > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/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/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/