"But unlike postal codes in other countries which represent small areas suitable for in-depth geographic inquiry (Google “N6C 2B5” for a Canadian example), ZIP

"But unlike postal codes in other countries which represent small areas suitable for in-depth geographic inquiry (Google “N6C 2B5” for a Canadian example), ZIP codes are woefully unqualified as units of analysis." First of all, don't Canadian zip codes have the exact same limitation? Postal codes in general are designed for the convenience of mail delivery and nothing else. (For that matter, mailing address often misidentifies the actual city of residence if one lives near a boundary and always states a phony city if one is in unincorporated territory.) There are two methods I can think of immediately to drill down into better detail. For one, zip codes are nine digits now, and using all nine digits (Zip+4) yields extremely narrow detail (generally no larger than the destination's building; often, homes have their own Zip+4. But that still leaves the problem of matching address to political boundary. For that, there are many datasets that match street address to the underlying parcel, and knowing the parcel provides you with actual city (if in incorporated territory), state political district(s), city political district, Congressional district, etc. It's used by mailhouses for sending political mailers to the correct jurisdiction all the time.