Blog Post

Insight: What does the Gini coefficient show us?

By: Mallory Bateman

Note: The opinions expressed are those of the author alone and do not reflect an institutional position of the Gardner Institute. We hope the opinions shared contribute to the marketplace of ideas and help people as they formulate their own INFORMED DECISIONS™.

In the past several weeks, I have gotten a few data requests asking for Gini coefficients at various levels of geography. The Gini coefficient, which is a value from 0 to 1, represents the income inequality across a population, with lower values indicating less inequality and higher values indicating greater inequality. This focus on income distribution provides one economic view of a community, but the measure has significant limitations.

As I examined Gini coefficients for states, metropolitan areas, and cities, I discovered that Utah and some of the places within it have some of the lowest values (most equal income distributions) in the nation. Of cities with populations over 100,000 nationwide, the #1 and #6 ranking fell to West Jordan and West Valley City. From previous research for Salt Lake County and Salt Lake City, I learned that West Jordan and West Valley have very different socioeconomic and demographic characteristics. Gini coefficients measure similarity or difference within an area, not between areas. Bottom line: communities with very similar Gini coefficients can be very different from each other.

The differences that struck me were those impact the economic status of a household or individual. Educational attainment and median household incomes are higher in West Jordan than West Valley, while the share of households in poverty is higher in West Valley. Another question that came to mind was the current environment of COVID-19. West Valley City accounts for nearly 12% of the total county population but is home to over 17% of cases. West Jordan is home to 10% of the population an