The high and rising degree of income inequality in the United States now exceeds the highest disparity, recorded in 1927. News coverage of this issue often emphasizes the shares of income and wealth of the top 1 percent versus the 99 percent. It should interest the folks of greater Seattle that, as apparent as income inequality is in the urban landscape, our city is amazingly one of the least unequal metropolitan areas in the country — along with Minneapolis, Portland, and Salt Lake City. The most unequal metro areas are New York, Miami, Los Angeles, Houston and San Francisco.
It will not take a statistician to spot the key difference between these two urban sets — predominantly white versus high minority share areas, reflecting the historical effects of discrimination on income opportunities. Still, inequality is great and visible on the landscape.
It is also now possible to compare degrees of inequality within metro areas. Reasonable estimates of mean and median income have recently become available at the zip code level. This household data, which comes from the Internal Revenue Service (2009 to 2011), allows for mapping the geography of income differences, and also estimating inequality in the distribution of income.
Median household income is considered the “typical” income of an area; that is, the income of the middle household when all households are ranked from lowest to highest. Median household income is not affected by extremes.
Mean household income is the aggregate income of all households in an area — the areas in this case being zip codes — divided by the number of households. Mean income is extremely affected by even a few very rich or very poor households. The mean income of an area is usually higher than the median, which reflects the high concentration of wealth in the top 1 percent in contemporary America.
Inequality is a measure of how far the distribution of incomes differs from a situation in which all households had the same income. I use a simple measure of the inequality of income, which is the difference between the median and mean, divided by the median — or the percent by which the mean is higher than the median. Values above .35 are considered quite high.
It is the local juxtaposition of poor and rich households that leads to inequality. So it should not surprise that areas of high inequality tend to have a mix of richer families and single people, who may not be poor, but lower in income compared to families, which may have more earners.
Because the median represents the middle household in an area, it is considered the best descriptive measure of an area’s relative income. The greater Seattle income map will, for the most part, be what the informed reader expects, but it holds a few surprises.
Median income levels in greater Seattle
Let me explain the map. This shows median income by zip code, from highest to lowest: Brown, $90,000 to $175,000. Magenta, $70,000 to $90,000. Yellow, $50,000 to $70,000. Green, $25,000 to $50,000. White, $25,000 or less.
You'll notice the prominence of the magenta ($70,000 to $90,000 income) category, and it's basically a good sign about the region. It reflects the fact that the Seattle metro area is much richer than the rest of the state. It extends largely over the predominantly suburban and exurban single-family home neighborhoods, covering about one-third of the greater Seattle region, although it also includes some upper-middle class, single-family home Seattle city neighborhoods.
The areas of highest incomes over $90,000 will offer no surprise (unless one expected more in Seattle), with most of the richest household areas in a contiguous belt in Eastside King County into Snohomish, and also Mukilteo, Bainbridge, and Fox Island (Pierce). In Seattle, only Magnolia and Montlake-Madrona (98112) pass the threshold. The reason is simply that most of Seattle has so many single earner households compared to the more family-heavy Eastside suburbs. The very richest zip codes? Medina (98039), Sammamish (98074, 98075), Mercer Island (98040), Cottage Lake to Redmond ( 98077, 98053), Eastgate-Newcastle (98006), Snoqualmie (98065) and Preston (98050) — all over $100,000.
Snoqualmie and Preston were small, poor and rural towns not so long ago. Medina's Zip 98039 has by far the highest median and mean incomes in the state: $175,000 and $290,000, respectively.
Areas with a typical middle income range of $50,000 to $70,000 (in yellow) include the less affluent parts of Seattle — often with sizeable minority populations — much of southwest King County, much of Tacoma and many small town or rural areas in Pierce and Thurston counties. Poorer areas may be a surprise. They include all military bases, because of the large share of young singles, but also parts of old central city downtowns: Seattle, Tacoma, Everett and Bremerton.
Even in Seattle, those wealthy penthouse folks are outnumbered by singles, a mixture of classes. Some lower income rural areas remain beyond the exurban zone. South Tacoma, Everett and SeaTac-Tukwila stand out as moderately poor (green). The poorest zip codes, all below $34,000, are Snoqualmie Pass-Roslyn (98068); Downtown Seattle (98101 and 98104) despite those few very rich residents there; Downtown Tacoma, Parkland (98447) and Fort Lewis (98439).
The map of relative inequality is rather different. Starting with the most unequal (in brown), the extreme is a tiny downtown Seattle zipcode 98164, but others with a high degree of inequality, an index over .5, include Medina (98039), the University District-Laurelhurst (98105). Montlake-Madrona again (98112), 98119 (West Queen Anne), north Capitol Hill (98102), downtown Seattle (98101, 98104), downtown Tacoma (98402), and the port of Tacoma (98421).
Income inequality in greater Seattle
Variances in income reflect inequality, from highest inequality to lowest: Brown, .50 or greater variance. Magenta, .25 to .50. Yellow, .15 to .25. Green, 0 to .15. White, -.11 to 0.
Moderately high inequality (.25 to .5, magenta) occurs in some affluent often waterfront areas, some areas with high levels of minorities, as in southeast Seattle, and in Tacoma, and generally in central Seattle, with its mix of families and singles. Redmond, central Bellevue, Lakewood and Edmonds are similarly high because of the mix of housing and household types.
Slightly below average inequality (.15 to .3, in yellow) is common in inner older urban areas, , e.g., Ballard, Greenwood, but also in rural and waterfront amenity areas with perhaps a mix of long-time residents and newer retirees — e.g., Vashon, Whidbey Island and Jefferson County. Low inequality ( less than .15) characterizes most of the predominantly single-family home areas of far suburbia and exurbia, but also a few inner city areas with little class variation, such as South Tacoma. The lowest inequality (0 to .15) is mainly in rural, small town areas, e.g. Yelm (98597), the neighboring towns of Sultan and Gold Bar (98294, 98251), Rainier (98576), Dupont (98327) and Orting (98360) but also suburban towns like Marysville (98270) and Duvall (98019), and some military areas like Camp Murray (98430), the Bremerton Naval shipyard and the Whidbey Island Naval air station (just off the map).
The story from all of this is that while a fairly simple geography of richer, middle and poorer neighborhoods is visible and familiar, for inequality the picture is more complicated, affected by the mix of housing and of kinds of households. That's especially true in gentrifying and densifying inner cities, most obviously Seattle. Essentially, areas of greater local economic and social diversity exhibit higher inequality, while more homogenous areas, dominated by single-family homes across the spectrum from poor to rich, are less unequal in their income distributions.
We may also conclude that, while we may decry the degree of inequality in our society and region, at a local level areas of high inequality are not "worse" nor areas of lower inequality "better," as many would argue that more diversity is healthy.
We do not have the data to compare these recent figures with a time of lesser inequality, notably the 1970-to-1980 decade. But it may be argued that local inequality has increased greatly, mainly because of a greater mix of housing and kinds of households, as a consequence of demographic and social change as well as growth management-induced urban redevelopment. And at the local level, that is what people seem to want.
Maps by Dick Morrill
