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From |
"Yu Chen, PhD" <profyuchen@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Find the fiscal year for each obs |

Date |
Sat, 6 Apr 2013 09:24:16 -0500 |

Nick, Thank you so much for the code. It works great. However, I have a further question. Assume File A has 5000 firms, and each has 360 daily stock price observations for 5 years, then there are 9,000,000 observations in File A. Assume File B has 5 years data (i.e., fiscal year definition) for each firm, then there are 25,000 observations in File B. If I use -merge-, the resulting file will be too large for the computer to handle. So I think some kind of loop structure might need to be used. Or there may be a better solution. Could you please help me in this regard? What code will be good to handle this problem? Best, Yu Chen On Sat, Apr 6, 2013 at 6:50 AM, Nick Cox <njcoxstata@gmail.com> wrote: > I'd just -merge- the files. The convention seems to be that Fiscal > Years are labelled by the year they start in. (It's _always_ a good > idea to explain stuff that won't be universally understood; assuming > that people work in your field is usually wrong.) Either way, there's > a correction for dates that are in calendar years that differ from > fiscal years. This example uses slightly different fake data. I used > an ancient -merge- only because I am writing from an ancient machine. > (I have Stata 12, but this machine doesn't read DVDs.) > > clear > input str3 Firm str10 Date > IBM "2009/01/15" > IBM "2010/01/16" > 3M "2010/07/01" > 3M "2011/07/02" > end > gen Ndate = date(Date, "YMD") > gen Fiscal = year(Ndate) > sort Firm Fiscal > save FileA, replace > > clear > input str3 Firm Fiscal str10 Begin str10 End > IBM 2009 "2009/03/01" "2010/02/28" > IBM 2010 "2010/03/01" "2011/02/28" > 3M 2010 "2010/06/01" "2011/05/31" > 3M 2011 "2011/06/01" "2012/05/31" > end > > gen Nbegin = date(Begin, "YMD") > gen Nend = date(End, "YMD") > sort Firm Fiscal > > version 10: merge Firm Fiscal using FileA > > replace Fiscal = Fiscal - 1 if !inrange(Ndate, Nbegin, Nend) > drop _merge > list Firm Fiscal Begin End Date > > > Nick > njcoxstata@gmail.com > > > On 6 April 2013 12:15, Yu Chen, PhD <profyuchen@gmail.com> wrote: > >> I have two files. File A contains the daily stock price for each firm, >> and file B contains the beginning and ending dates for a fiscal year >> for each firm. See below for an illustration (data are hypothetical): >> >> File A: >> Firm Date Price >> IBM 2009/01/15 xxxx >> IBM 2009/01/16 xxxx >> ................... >> 3M 2010/07/01 yyyy >> 3M 2010/07/02 yyyy >> ................... >> >> File B: >> Firm Fiscal Year Beg. Date End. Date >> IBM 2009 2009/03/01 2010/02/28 >> IBM 2010 2010/03/01 2011/02/28 >> .................. >> 3M 2010 2010/06/01 2011/05/31 >> 3M 2011 2011/06/01 2012/05/31 >> .................. >> >> Now, I want indicate in File A for each observation the fiscal year >> the observation belongs to, according to the definition in File B. >> Conceptually it seems easy: Just compare the date of the observation >> in File A with the beginning and ending dates in File B. > * > * 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/

**Follow-Ups**:**Re: st: Find the fiscal year for each obs***From:*Tom <tommedema@gmail.com>

**Re: st: Find the fiscal year for each obs***From:*Nick Cox <njcoxstata@gmail.com>

**References**:**st: Find the fiscal year for each obs***From:*"Yu Chen, PhD" <profyuchen@gmail.com>

**Re: st: Find the fiscal year for each obs***From:*Nick Cox <njcoxstata@gmail.com>

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