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Stop using zip codes for geospatial analysis (2019)

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Re: Stop using zip codes for geospatial analysis (2019)

#121

Post by ericrallen »

VWWHFSfQ wrote: post #54
nitwit005 wrote: post #39

Earlier quoted context omitted.

Yes, unfortunately, their assertion that everyone knows their zip code is wrong. People often write a neighboring code, and the post office just delivers it. Similar issues for city name, of course.

Very common in NYC. People will use all of "New York, NY", "Queens, NY", or "Astoria, NY" all interchangeably and the post office will still just deliver it to the same place.

This is sort of apocryphal - and also anecdotal because I have my own personal experience living in an annexed Boston neighborhood to draw on - but in a lot of the towns/neighborhoods that have been annexed by Boston, people still use the neighborhood name[1] as the city name because you are more likely to get your package when you indicate which “Washington St,” “Boylston St,” etc. you actually live at.

According to one commenter on the subject:

  It doesn't matter, as long as the zip code is correct
[0]: https://www.city-data.com/forum/boston/601106-mailing-addres...

[1]: https://www.city-data.com/forum/boston/601106-mailing-addres...

Re: Stop using zip codes for geospatial analysis (2019)

#122

Post by tbrownaw »

steezeburger wrote: post #84
nitwit005 wrote: post #39

Earlier quoted context omitted.

Yes, unfortunately, their assertion that everyone knows their zip code is wrong. People often write a neighboring code, and the post office just delivers it. Similar issues for city name, of course.

This sounds like the person doesn't know the receiver's zip code. Why are you extending that to not knowing their own zip code? Are they mailing something to themselves?

I will occasionally still try to use the zip code for my old work address (from about a year before covid) when what I want is my home address.

Re: Stop using zip codes for geospatial analysis (2019)

#123

Post by stevage »

I still miss carto.com (originally CartoDB).

It was a really useful platform for uploading spatial data with a decent range of visualisation tools that didn't need code. You could do SQL if you wanted.

Then they got rid of the free tier, and set the cheapest tier at (iirc) $150 USD per month. And that was the end of that.

Re: Stop using zip codes for geospatial analysis (2019)

#124

Post by stevage »

jonas21 wrote: post #14

ZIP codes are an emergent property of the mail delivery system. While the author might consider this a bad thing, this makes them "good enough" on multiple axes in practice. They tend to be: - Well-known (everybody knows their zip code) - Easily extracted (they're part of every address, no geocoding required) - Uniform-enough (not perfect, but in most cases close) - Granular-enough - Contiguous-enough by travel time…

> Easily extracted (they're part of every address, no geocoding required)

That's only true if you can also access the spatial boundaries of the zipcodes themselves.

In Australia, this turns out not to be true: the postal system considers their boundaries to be commercial confidential information and doesn't share them. The best we can do is the Australian Bureau of Statistics' approximations of them, which they dub "postal areas".

Re: Stop using zip codes for geospatial analysis (2019)

#125

Post by freyfogle »

vikingerik wrote: post #119
freyfogle wrote: post #66

There are many problems with zip codes / postal codes but the biggest two we see are: a. Excel treats them as numbers instead of strings of digits and thus drops the leading 0 b. Developers make assumptions about postal codes based on how they work (or more usually how the developer incorrectly thinks they work) in their own country and these assumptions absolutely do NOT hold in other countries. A relevant guide to…

The post office has adapted in turn to that Excel problem. They know it happens. If a parcel has only four digits for the zip code, they'll treat it as a leading zero for routing and delivery.

yes, of course. The question is have all the developers writing their own code to deal with zip codes also adapted?

Re: Stop using zip codes for geospatial analysis (2019)

#126

Post by BiteCode_dev »

NelsonMinar wrote: post #109
jihadjihad wrote: post #4

To put it in plain mathematical language, ZIP codes are not defined as polygons [0]. The consequence is that performing any analysis with an assumption that ZIP codes are polygons is bound to be error-prone. 0: https://manifold.net/doc/mfd8/zip_codes_are_not_areas.htm

That's not the important problem and there's a simple solution with ZCTAs. The big problem is zip codes are defined in terms of convenient postal routes and aren't suitable for most geospatial analysis. Census units, as the article explains, are a much better choice.

You ask a customer their census unit on purchase though.

Re: Stop using zip codes for geospatial analysis (2019)

#128

Post by maxerickson »

alsodumb wrote: post #38
cogman10 wrote: post #20

Earlier quoted context omitted.

Zip codes (in the US) are machine readable numbers a mail sorter can use to send a parcel to the right delivery truck for final delivery. In the US, they represent the hierarchy of postal centers with the most significant digit representing the primary hub for a region and the smallest number the actual post office that will be in charge of delivering the letter (or truck if you do the extended post code). They don't…

I agree that they weren't explicitly meant to represent geography, but implicitly they do, right? Are there cases where this is violated? In other words, is it safe to assume that for entity in a zip code is less than x distance away from the closest entity in the same zip code?

They do provide a location with whatever error bars on it.

What they do not have is any sort of spatial consistency, they are a convenience for mail sorting. So if you start analyzing patterns across zip codes, you are pulling in information that is likely useless for or harmful to answering your question.

Re: Stop using zip codes for geospatial analysis (2019)

#129

Post by talkingtab »

There should be a desensationalizer for titles on HN. When I read this it tricks my brain:

Stop using zip codes

BANG! Why should I stop using zip codes? Must read!!!

And then you go to the old (2019) page, that appears to be filled with useless clicks and arguments that appear biased.

"Do not use zip codes for geospatial analysis."

Re: Stop using zip codes for geospatial analysis (2019)

#130

Post by jwnacnud »

Amen! ZIP Codes (if referring to the US Postal Service) were only ever made for the purpose to sorting and delivering mail more efficiently. ZIP Codes serve the purposes of the US Postal Service, full stop. They don't respect any political or geographical boundaries - and they change at the whim of the USPS, as they were created and are maintained to suit their needs.

If used for other purposes they fall short.

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