Child Opportunity Index 2.0 ZIP Code data

The Child Opportunity Index (COI) 2.0 ZIP code data are ZIP code level estimates of neighborhood opportunity derived from 2015 COI 2.0 census tract data. COI 2.0 census tract data is available here. We created ZIP code level COI 2.0 estimates for data users who – for different reasons – cannot work with census tract COI data. It is important to note that for all COI 2.0 ZIP code data files, neighborhood conditions were measured in and around 2015. The years in the data file titles DO NOT denote the years in which neighborhood conditions were measured but refer to the ZIP code definitions for a given year. Please refer to the COI 2.0 ZIP code data technical documentation for more detailed information. There are about 73 thousand census tracts (2010 definition) in the US that intersect with about 39 thousand ZIP codes. Unlike census tracts, ZIP codes do not have precisely defined geographic boundaries. They are collections of addresses defined by the U.S. Postal Service (USPS) for efficient mail delivery. Our method for aggregating census tract to ZIP code data uses weights published by the U.S. Department for Housing and Urban Development. ZIP code COI 2.0 estimates are calculated as the weighted average of census tract data, where census tracts that are home to a greater proportion of residential addresses with a given ZIP code receive greater weight. The weights used to calculate ZIP code level COI 2.0 data change continually because the USPS regularly updates ZIP codes, for example to incorporate newly constructed buildings/addresses. We therefore publish multiple ZIP code data files for the ZIP code definitions in a given year. For example, the file “COI 2.0 ZIP code data for 2020 ZIP codes” contains 2015 COI 2.0 data aggregated to ZIP codes as they were defined in 2020. We recommend users to use this file if their goal is to link it to another dataset with ZIP code data collected in 2020. If ZIP code data was collected over multiple years, we have created ZIP code estimates that average over ZIP code definitions for multiple years. Please contact us contact us to request access to these data.