INTRODUCTION
IMPLAN provides data at the ZIP code level. A single ZIP code can rarely be considered a functional economy, but combining ZIP codes to build a particular Region is a great way to create a functional economy with a custom geographic boundary. When working with Zip Code level data, there are several factors to consider. This article, while not exhaustive, lists the main items to keep in mind when using Zip Code data for your geographical study Region.
AGGREGATION & LEAKAGES
Zip code, like other IMPLAN data, can be combined to create a Region or used independently. Please keep in mind that while an individual zip code model will contain Multipliers and thus can be used for impact analysis, the resulting impacts will be minimal. This is because zip codes may have little or no population and/or little to no employment. Also, many individual zip codes are not large enough to allow for local sourcing of goods and services needed for the indirect effect or to provide adequate services to create significant induced effects leading to much of the potential impact being lost in leakages. One option is to consider MRIO which estimates the interregional linkages of trade and commuting effects.
Most often, a county is the smallest advisable Region for impact Analysis. However, in cases where one portion of a county is very distinct from another (for example, a city in an otherwise rural county), it may be justifiable to build a smaller Region model made up of several zip codes.
FEW RAW DATA SOURCES
The smaller the geographic unit, the fewer raw data sources available. Thus, zip code based models rely more heavily on estimation techniques for many data elements for which there are no raw data at the zip code level. For more information on the data sources and methods used for IMPLAN’s zip code data, read our support article Estimating Zip Code Data.
ZIP CODE LISTS
The list of zip codes for which IMPLAN creates models varies from one year to the next based on raw data availability, and may differ from lists of zip-codes found elsewhere, such as the U.S. Postal Service. In order to produce a complete IMPLAN model for a given zip code, the zip code must have either demographic data (e.g., population) or industry data (e.g., employment). For more details, please see this article on the data sources and methods used for IMPLAN’s zip code data.
RELATED ARTICLES
Introduction to Regional Models in IMPLAN
MRIO: Introduction to Multi-Regional Input-Output Analysis
Updated September 13, 2024