Household Income in King County
Median Household Income in King County is the highest of its peers.
As of 2018, median household income in King County was $95,009. For the purpose of comparison, we also looked at income data from King County’s “Peer Counties,” which, together with King County, make up the ten largest US counties by employment as measured by the U.S. Bureau of Labor Statistics (BLS). King County is the ninth largest U.S. county by employment. The peer counties are Maricopa County, AZ (which contains Phoenix); Los Angeles County, CA; Orange County, CA; San Diego County, CA; Miami-Dade County, FL; Cook County, IL (Chicago); New York County, NY; Dallas County, TX; and Harris County, TX (Houston).
Household Income has grown rapidly despite the occurrence of two recessions since 2000.
Household income in King County increased from $53,157 in 2000 to $95,009 in 2018, an increase of over 78%. Among its peer counties, only New York experienced a faster rate of increase between 2000 and 2018.
At least part of the increase in household income in King County is attributable to the increase in both the number of jobs in the high-paying information and technology sector, as well as the rapidly increasing wages paid within the sector. While overall King County average annual wages increased 76% between 2005 and 2018, average annual wages for an information worker increased 127% over the same time period.
King County appears to have better overall income equality than most of its peers.
To measure income inequality, the US Census Bureau calculates the Gini Index for each county. The Gini Index measures how much the distribution of income among individuals within an economy deviates from a perfectly equal distribution. A Gini Index of 0 equates to perfect equality, while 1 equates to perfect inequality. King County registered a Gini Index of 0.47 in 2018, just lower than the United States’ 0.48 and well below New York County’s 0.59.
A closer look reveals widening gaps in income within King County.
Looking closely at the household income quintiles for King County, we observe a widening gap between the upper and lower quintiles. However, income in the lower quintiles have begun making gains. In 2018, 20% of King County households earned $40,214 or less. This represents an increase of 45.5% over the 2006 figure of $27,634, not adjusted for inflation. The second lowest quintile experienced 48% income growth between 2006 and 2018. Between 2013 and 2018, the lower two quintile experienced the fastest income growth, with household incomes increasing between 34% and 36%, making up for sluggish growth during the recession and immediately thereafter.
The third quintile saw incomes increase 51% from 2006 to 2018. The 20% of King County households in the fourth quintile saw their incomes rise by 55%.
Things get tricky for the very top quintile, which includes households earning greater than $184,264 in 2018. It is difficult to accurately measure the increase in these households' income as income data is not provided for households with incomes greater than $250,000 to protect privacy. We do know that the lower limit increased by 55% (from $118,733 to $184,264) from 2006 to 2018. The Census also provides the lower bound for the top 5% of household incomes (plotted in light blue on the chart) and this value increased by at least 16%, from $216,092 to $250,000+. However, since the value has remained at "$250,000+" since 2013, the actual increase is likely quite a bit larger, particularly given the trend of higher income increases as you move up the quintiles.
Another concerning gap occurs when household income in King County is broken down by race. Median incomes for white and Asian households far exceed those of black or Latino households. While this is true across all of King County’s peer counties, the gap between white and black incomes in King County is among the widest in the group. In 2018, the median household income for a black household was $55,152 – or 55% that of a white household’s median income of $100,298. Among the peer counties, only New York County and Cook County (Chicago) had a wider gap between black and white households.
King County has begun to make progress in reducing the gap (albeit slowly.) From 2000 to 2015, white households in King County experienced steadily increasing incomes while the median income for black households have experienced far slower growth. This trend finally reversed between 2015 and 2018, with white households experiencing 16% growth in median income compared to a 30% increase for black households. The gap between Latino and white households also widened from 2000 to 2015 before reversing in the last three years. However, for both black households and Latino households, the gap is still wider than it was in 2000.
Data for Median Household Income by County and by Race, Gini Coefficient, and Income Quintiles was taken from the American Community Survey via the US Census Bureau.
Data for average wages by industry was taken from the Washington State Employment Security Department.