Notice: On March 31, it was **announced** that Statalist is moving from an email list to a **forum**. The old list will shut down on April 23, and its replacement, **statalist.org** is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From |
Tom <tommedema@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

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

Date |
Sat, 6 Apr 2013 16:45:25 +0200 |

Dear Yu Chen, It might be that the discussion at http://www.nber.org/sys-admin/large-stata-datasets.html is helpful to you. It specifically addresses large datasets. Kind regards, Tom On Sat, Apr 6, 2013 at 4:24 PM, Yu Chen, PhD <profyuchen@gmail.com> wrote: > 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/ * * 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:*"Yu Chen, PhD" <profyuchen@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>

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

- Prev by Date:
**Re: st: Find the fiscal year for each obs** - Next by Date:
**Re: st: Identify Closest Subsequent Date** - Previous by thread:
**Re: st: Find the fiscal year for each obs** - Next by thread:
**Re: st: Find the fiscal year for each obs** - Index(es):