As a consequence, ZIP Code “areas” can overlap, be subsets of each other, or be artificial constructs with no geographic area (such as 095 for mail to the Navy, which is not geographically fixed). ZIP codes themselves do not actually represent an area, rather a collection of routes:ĭespite the geographic derivation of most ZIP Codes, the codes themselves do not represent geographic regions in general, they correspond to address groups or delivery routes. The five-digit code represents a part of the country (5_ _ _ _ ), a sectional center facility ( _ 5 4 _ _ ), and the associate post office or delivery area (_ _ _ 1 6). But with more and more mail being sent, in 1963 the Postal Service decided to roll out the Zone Improvement Plan, which transformed addresses to look like the following: “16” represents the postal zone in a Minneapolis. The predecessor to the zip code was the postal zone, which represented a post office department for a specific city.

To understand why this is, we first need to understand a little more about the zip code itself. The problem is that zip codes are not a good representation of real human behavior, and when used in data analysis, often mask real, underlying insights, and may ultimately lead to bad outcomes. It is used to make major decisions for marketing, opening or closing stores, providing services, and making decisions that can have a massive financial impact. They are deciding how to use data tied to those zip codes to understand trends, run their businesses, and find new ways to reach you, using that same five-digit code.Įven though there are different place associations that probably mean more to you as an individual, such as a neighborhood, street, or the block you live on, the zip code is, in many organizations, the geographic unit of choice.

However, lots of companies, marketers, and data analysts spend hours looking at zip codes.

You likely found the answer you were looking for and didn’t stop to think further about that five-digit code you’d just typed out. The last time you used your zip code, you were most likely entering your address into a website to make a purchase, finding a store near your home or office, or filling out some other online form. Stop Using Zip Codes for Geospatial Analysis

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