Mr. Dykstra,
> I happily found your on-line list of NPA/NXX's (area code plus exchanges)
> with some geographic information attached.
> I work for a non-profit which is just about to conduct a telephone
> survey of rental households in Los Angeles, and we are seeking maps
> (or mapable information) about telephone numbers. When we call renters
> (as well as smaller sample of apartment owners), we want to know if
> they fall in the City of Los Angeles or an adjacent community.
> My understanding is that telephone exchange numbers can represent
> geographic areas, similar to a ZIP code area or census tract. Is > that the case?
No. Many people have ported their number to a cell phone. When they move they take that number with them. Ok, that is true of some percentage and that may be enough for your purpose. But to tell if a given, single number is "somewhere" - don't count on it!
[TELECOM Digest Editor's Note: But I think it would be fair to say that although local number portability is possible, not that many people have taken advantage of it; certainly not that far out of the original area of the number. Having said that, now I suppose I will hear about a New Yorker who took his 212 number to California or vice- versa, but it is still relatively rare. PAT]