Terra Curtis writes:
> I have a dataset like the sample shown below:
>
> firm patent stageatsigning date awddate2
> stagedummy
> .
> .
> .
> 285 4401756 12/01/96
> 08/30/83 0
> 285 4401756 11/01/84
> 08/30/83 0
> 285 4401756 01/01/93
> 08/30/83 0
> 285 4401756 09/01/93
> 08/30/83 0
> 285 4401756 08/01/94
> 08/30/83 0
> 285 4401756 09/01/90
> 08/30/83 0
> 285 4401756 04/01/96
> 08/30/83 0
> 285 4401756 12/01/95
> 08/30/83 0
> 285 4401756 10/01/96
> 08/30/83 0
> 285 4401756 07/01/88
> 08/30/83 0
> 285 4401756 Approved 12/01/92
> 08/30/83 0
> 285 4401756 Discovery 02/01/92
> 08/30/83 0
> 285 4401756 Discovery 02/01/95
> 08/30/83 0
> 285 4401756 Discovery 01/01/86
> 08/30/83 0
> 285 4401756 Discovery 01/01/96
> 08/30/83 0
> 285 4401756 Formulation 08/01/95
> 08/30/83 0
> 285 4401756 Lead Molecule 09/01/85 08/30/83 0
> 285 4401756 Lead Molecule 10/01/81 08/30/83 0*
> 285 4401756 Lead Molecule 04/01/83 08/30/83 0**
> 285 4401756 Lead Molecule 04/01/93 08/30/83 0
> 285 4401756 Lead Molecule 10/01/84 08/30/83 0
> 285 4401756 Phase I, Approved 01/01/92
> 08/30/83 0
> 285 4401756 Phase II 12/01/93
> 08/30/83 0
> 285 4401756 Preclinical 04/01/96
> 08/30/83 0
> .
> .
> .
>
> What I want to do is determine which 'stageatsigning' the
> patent was in at the 'awddate2' So, for this example, I want
> to replace stagedummy=1 on the line marked with * since the
> 'awddate2' is between the 'date' on that line
> and the date on the line marked **. Any suggestions for how
> I could do this?
* if date and awddate2 not in Stata date format, gen versions in Stata date format
gen date1=date(date,"md19y")
format date1 %d
gen awddate1=date(awddate2,"md19y")
format awddate1 %d
* then
bysort patent (date1): replace stagedummy=1 if date1< awddate1
by patent: replace stagedummy = 0 if stagedummy[_n+1] == 1
* else if both date and awddate2 in Stata date format
bysort patent (date): replace stagedummy=1 if date< awddate2
by patent: replace stagedummy = 0 if stagedummy[_n+1] == 1
Tom
-----------------------------------------
CONFIDENTIALITY NOTE: This e-mail message, including any attachment(s),
contains information that may be confidential, protected by the
attorney-client or other legal privileges, and/or proprietary non-
public information. If you are not an intended recipient of this
message or an authorized assistant to an intended recipient, please
notify the sender by replying to this message and then delete it from
your system. Use, dissemination, distribution, or reproduction of this
message and/or any of its attachments (if any) by unintended recipients
is not authorized and may be unlawful.
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
