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Re: st: Oddities with weekly data


From   "Austin Nichols" <austinnichols@gmail.com>
To   "Michael S. Hanson" <mshanson@mac.com>, statalist@hsphsun2.harvard.edu
Subject   Re: st: Oddities with weekly data
Date   Fri, 19 May 2006 15:59:32 -0400

My approach (generating your own week variable, essentially, bypassing
the wofd() function) would solve the Mon/Tue problem and the week 52
problem, but assuming there are no missing weeks, your alternative of
using _n seems just as good or better.  The oddity of weeks is that
Stata constrains there to be only 52 weeks in a year, and the week
numbering starts over on Jan 1 of each year, which means that week 52
in any year is either 8 or 9 days long.  Having repeated time values
in a weekly time series is nearly inevitable given these definitional
constraints.

clear
range t 12040 12060 21
gen twk = wofd(t)
gen d=t
format d %d
li, noo sep(7)


On 5/18/06, Michael S. Hanson <mshanson@mac.com> wrote:
As an alternative, I could just -tsset- with a simple time trend:

//
sort t
gen trend = _n
tsset trend
//

...but that has the disadvantage that the time variable doesn't have
any natural units;  thus one cannot use the -tin()- functions for
selecting subsamples, dates don't show up correct on the t-axis of
graphs, etc.

So I'm still a bit stuck -- something apparently is still "odd" with
these data -- but I do appreciate your help.  As I mentioned above, any
additional thoughts would be most welcome.  Thanks again.

                                        -- Mike
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