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Income Inequality

General information

Income inequality refers to the distribution of household income compared to the number of households, which can be measured with the Gini Coefficient, a score of 0 represents complete equality and a score of 1 represents complete inequality. Areas with gaps in income equality are more likely to have poorer health outcomes such as life expectancy, infant mortality, and obesity.1

Source: California Department of Public Health, Income Inequality: Household Income relative to the number of households (Gini Index), 2014

Key Findings

  • San Mateo County has a Gini Coefficient of 0.46, one of the highest among Bay Area counties indicating that it has one of the highest inequalities of the 9-county region.
  • The cities of Burlingame and Menlo Park have the highest Gini Coefficient of 0.51, indicating these two cities have the largest income disparities.
  • Daly City has the lowest income disparity with a Gini Coefficient of 0.37.


  • Data were obtained from the California Department of Public Health’s Healthy Communities Data and Indicators Project.
  • The Healthy Communities Data and Indicators Project used 2008-2010 American Community Survey 3-year Estimates.


  • The Gini Coefficient measures only the distribution of wealth and poverty and not the magnitude.
  • The Gini Coefficient is based on American Community Survey data, which are estimates based on survey responses and not actual counts.


  1. California Department of Public Health, Healthy Communities Data and Indicators Project