st: smoothing question

["DeMichele, Matthew" <mdemichele@rti.org>]

This may be outside the scope of the listserve, but I'm going to throw
it out just in case someone has ideas. My situation is more
methodological than software driven. I'm tasked with adjusting
time-series data from 1980-2010 of about 480 respondents reporting
administrative data for two time points in a single year. For instance,
a respondent is asked in January of 2010 to report December 31, 2009 and
January 1, 2009 populations. This is repeated annually. What we've
noticed is that December 31, 2009 populations sometimes have large
differences with January 1, 2010 (one day). It could be that an
administrative or legal change took place, or even a recording error. My
question is if anyone has advice for whether this seems to be best
addressed with an ARIMA or exponential smoothing model. Or, if the
Census X-12-ARIMA model/software if a better approach to address extreme
values/trading-day adjustments.  

My apologies in advance if this is not something that fits the
listserve. 

Matthew 



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