st: spatial weights which also take into account time

["Ben Hoen" <bhoen@lbl.gov>]

Hi all,

I have been unsuccessful in my search this morning for a way to deal with
both space and time (or for that matter any other variable other than space)
in developing a spatial weights matrix.  ALERT: I am a novice - slowly
learning - about spatial models.

The k nearest neighbors options in some user written programs (e.g.,
spwmatrix - SSC) allows me to limit the number of neighbors based on
"nearness".  Alternatively I could use some cutoff distance (e.g., 1 mile)
to limit the collection of "neighbors".  But in addition to distance I would
like to use time to limit my data.  For example I have home transactions
that I want to test for spatial autocorrelation between.  I concern myself
with BOTH the k (e.g., 5) nearest neighbors that ALSO transacted within the
previous year.  (I.e., using a transaction that occurred, for example, 10
years later does not make sense, even if it is "nearest".)  

Are there any ideas out there for how to limit the data based on both space
AND time in developing the weights matrix?

Ben

Ben Hoen
Principal Research Associate
Lawrence Berkeley National Laboratory
Office: 845-758-1896
Cell: 718-812-7589
bhoen@lbl.gov
http://emp.lbl.gov/staff/ben-hoen

Visit our publications at: 
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