About the DCI
The Distressed Communities Index (DCI) brings attention to the deep disparities in economic well-being that separate U.S. communities. The latest Census data is used to sort zip codes, counties, and congressional districts into five quintiles of well-being: prosperous, comfortable, mid-tier, at risk, and distressed. The index allows us to explore disparities within and across cities and states, as well.
The seven components of the index are:
- No high school diploma: Share of the 25 and older population without a high school diploma or equivalent.
- Housing vacancy rate: Share of habitable housing that is unoccupied, excluding properties that are for seasonal, recreational, or occasional use.
- Adults not working: Share of the prime-age (25-54) population that is not currently employed.
- Poverty rate: Share of the population below the poverty line.
- Median income ratio: Median household income as a share of metro area median household income (or state, for non-metro areas and all congressional districts).
- Changes in employment: Percent change in the number of jobs over the past five years.
- Changes in establishments: Percent change in the number of business establishments over the past five years.
Data sources
The primary data source for the DCI is the U.S. Census Bureau’s American Community Survey (ACS) 5-Year Estimates. These ACS estimates are multiyear averages that provide the most statistically reliable data for smaller geographic units, such as zip codes and less populated counties. Census Business Patterns data is used to calculate employment and establishment growth.
Creating the index
Each zip code’s rank is averaged and weighted equally across all seven component metrics to create a preliminary score, which is then normalized into a final Distress Score ranging from approaching 0 (most prosperous) to 100 (most distressed). These scores are equivalent to percentiles. Communities are then sorted into five quintiles based on their score: prosperous, comfortable, mid-tier, at risk, and distressed. The same method is used to calculate scores for counties and congressional districts.
In all, the zip code-level DCI captures 99 percent of the U.S. population and around 26,000 zip codes with at least 500 residents (excluding those living in group quarters). The DCI is not calculated for Puerto Rico or the territories due to missing data.
Technical note on zip codes and ZCTAs
Zip codes provide a meaningful scale of analysis by often aligning with geographies of local life and capturing multiple neighborhoods and a mix of use cases (residential, commercial, and industrial) on the ground, but they are not exact representations of geographic areas or communities. They are defined by the U.S. Postal Service for deliveries, not by the U.S. Census Bureau for statistical purposes. Zip code boundaries can and do change over time for non-economic reasons. Reflecting their utility for sub-county economic and demographic analysis, however, the U.S. Census Bureau creates its own approximations of zip codes, called ZIP Code Tabulation Areas (ZCTAs), from census blocks once after each Decennial Census.
The DCI combines zip code-based data (Business Patterns) with ZCTA-based data (ACS) using matching codes, but the boundaries of zip codes and ZCTAs may be different and can change over time. Therefore, it is important to understand that zip code-level findings in the DCI represent general trends for an approximate area.
Missing data
In instances where the establishment or employment estimates from Business Patterns were absent or suppressed by the Census Bureau to preserve privacy, the DCI defaulted to the next-highest level geography to produce a growth estimate that could enter into the index. For example, if employment levels in a zip code were suppressed, it would be assigned its county’s employment growth rate. For a few zip codes lacking income data, county-level median household income ratios were used to determine their DCI scores.