----------------------------Original message----------------------------
>I know that zip code boundary files are not in the public domain, but
>they just keep asking...  Has anyone ever seen the area (as in sq. miles)
>of zip codes?  Five digit would be fine now, but you know he'll be back for
>+4.  This is for a population density question and the user has been advised
>that zips are not an appropriate statistical area...
 
Maybe your user is having trouble understanding what you are trying to tell
him. There is NO relationship between zipcodes and population density. A post
office with a single 5-digit code may serve 100 people, where another may
serve 30,000 or more and cover roughly the same number of square mile.
 
A slightly better indicator, if he insists on using zipcodes, would be the
3-digit codes (the first three of the five digits). Maps of these can be
found in the National Five-Digit Zip Code & Post Office Directory available
at any post office. However, these boundaries were established 30 years ago
and have changed very little.
 
My choice would be to sic him on the phone company. Area codes change
frequently and have some relationship to the number of telephones. Maps are
available in every phone book.
 
Art Lassagne (former USPS manager)
[log in to unmask]