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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)

#61

Post by hinkley »

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…

Contiguous enough by data travel time as well. A few people will get 5 ms more latency than the exact optimal route, but it’s not like your routes are exactly optimal anyway.

And don’t forget sales tax. Which is state + county + city

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

#62

Post by kylebarron »

hammock wrote: post #50
serjester wrote: post #22

H3 is awesome here! What I don't think many people realize is that H3 cells and normal geographic data (like zips) are not mutually exclusive. You can take zip outlines, and find all the h3 cells within them and allocate your metric accordingly (population, income, etc). This makes joining disparate data sources quite easy. And this also lets you do all sorts of cool stuff like aggregations, smoothing, flow modeling,…

What is the benefit of H3 vs a rectangular grid?

Equal distances to each adjacent neighbor: https://www.uber.com/blog/h3/

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

#63

Post by sophacles »

mmmlinux wrote: post #57

Can anyone tell me why I have to enter both my city / state and a zip code. shouldn't one or the other of those plus my street address be enough information?

Several posts in this thread have linked the recent GCP-gray video on the topic, and it addresses this question better than I can. It's pretty interesting actually

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

#64

Post by rented_mule »

ericrallen wrote: post #28
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…

This is a tangent, but addresses are also way more complicated than most people realize - especially if you’re relying on a user to input a correct address or if you need to support multiple countries, somewhere with unique addresses like Queens[0], or you need to differentiate between units of a specific street address that uses something other than unit numbers for a unit designation. At that point you need somethi…

An annoyance for me is that I've yet to see any address validator get my current home address right. They all insist my address is on the road that leads to my road rather than my actual road. It's understandable that they can't be 100% accurate given the scale / complexity of addresses.

Most sites/apps will let me override the validator, but a few won't. The most common ones that insist on using the wrong address are financial institutions that say the law requires them to have my proper physical address and therefore they go with the (incorrectly) validated version.

USPS does not do home delivery in our area, and UPS/FedEx/etc. usually figure it out given that street numbers alone uniquely identify properties in our town.

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

#65

Post by jayknight »

ubermonkey wrote: post #59
mmmlinux wrote: post #57

Can anyone tell me why I have to enter both my city / state and a zip code. shouldn't one or the other of those plus my street address be enough information?

Web devs not using a good library that will populate the former from the latter?

Some libraries will insist that my address is in a different city because my zip code spans the border. I mean if my mail has the other city it still gets to me, but for anything other than mail, they now have the wrong city for me.

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

#66

Post by freyfogle »

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 geocoding and postal codes: https://opencagedata.com/guides/how-to-think-about-postcodes...

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

#67

Post by mattforrest »

walrus01 wrote: post #43
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…

In terms of "good enough", a Canadian postal code, broadly equivalent to a zip code, is much more granular and can often identify an individual apartment building, or single city block. Plenty of large office buildings in major Canadian cities also have their own postal code. The functionality of it is closer to the "Zip+4" with extension used to have a more granular routing of physical mail for USPS. https://www.can…

Yeah but Zip+4 represent a collection of houses not a polygon so not useful for aggregations or statistical work

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

#68

Post by michaelmrose »

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…

If you are worrying about address at all instead of tax or legal jurisdiction its probable that you as a business have a physical presence. You can probably correlate better by predicting which location a given address would likely interact with if you don't know already by prior purchases/interaction which they normally do so. I would suggest actual purchase data followed by travel time.

Zip and distance as the crow flies often gives shit data. My zip suggests I'm off in bum fuck and since I'm on the puget sound things that are relatively near as the crow flies can actually be hours away.

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

#69

Post by mattforrest »

cogman10 wrote: post #20
mholt wrote: post #15

Earlier quoted context omitted.

Yeah. ZIP codes are sets in the abstract-dimensional space of carrier delivery points. I suppose you could think of them as lines, but definitely not polygons.

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…

Well put

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

#70

Post by bluGill »

ssl-3 wrote: post #60
walrus01 wrote: post #43

Earlier quoted context omitted.

In terms of "good enough", a Canadian postal code, broadly equivalent to a zip code, is much more granular and can often identify an individual apartment building, or single city block. Plenty of large office buildings in major Canadian cities also have their own postal code. The functionality of it is closer to the "Zip+4" with extension used to have a more granular routing of physical mail for USPS. https://www.can…

Sure, and in the States, ZIP+4 could once nail my postal location to a subset of 4 (of a group of 16) mailboxes within a particular set of entry doors on a particular apartment building. But broadly speaking, nobody knows what their ZIP+4 is, while I imagine that most people in Canada know their postal code by heart. It is interesting.

The plus four changes all the time so it isn't feasable to know it. The use is large mailers can get a discount by looking it up and presorting mail. If the mail coming into my post office has my mail next to my next door neighbors that saves them a lot of time.
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