A funny thing is happening in many US cities

An article at the Urbanophile gives us a helpful graphic explaining the old and new “Donut” conceptions of the city.  In the “Old Donut,” we have an impoverished central city with a ring of thriving suburbs around it.

OldDonutAn example of that model appears in this graph, which shows the percentage of adults over 25 with college degrees in the Charlotte, NC metro area in 1990.  The x-axis is distance from the center of downtown.


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How do we know whether development pays for itself?

Local governments across the country have come under increasing fiscal strain in recent years, with several being forced to declare bankruptcy.  The problems range from pension programs and decaying infrastructure to falling revenues from industrial and sales taxes as manufacturing gets offshored and shopping happens online.  In Virginia, cities are further constrained by annexation laws that prevent them from expanding with their metropolitan area and gaining revenue from greenfield development or wealthier suburbs.

Meanwhile, the high mobility of Americans and increasing specialization of metro areas and cities have forced localities to behave like competitors in a market for residents and businesses, rather than as simple political entities administering a group of people.  This makes it more important than ever for localities to understand which investments and spatial configurations create value and which don’t.  The immediate problem is that we lack good ways of approaching the question.

Property value per acre is a good start on the revenue side.  Not only is it influenced by different types of public investments that people want to be near, it’s also heavily influenced by local land use law – namely, how many people are allowed to live on a piece of land.  The assessed value, which is mapped here, determines how much revenue the locality generates via property tax.  That’s important because many of the costs cities have to bear are determined primarily by the amount of land they have to cover (see chart below).  That means that if land is not generating enough tax value per acre, some municipal services will be subsidized by other neighborhoods.  Others will simply have to be less comprehensive.  For instance, fire department and emergency response times are much longer in low-density areas, simply because people are farther away from stations.

Per Capita Expenditures

(vary primarily by number of peopled that must be served)


Per Area Expenditures

(vary primarily by amount of area that must be serviced)

  • Schools
  • Judicial systems
  • Health
  • Community Development
  • Fire
  • Sewage
  • Other utilities
  • Stormwater Management
  • Sidewalks
  • Streetlights
  • Roads
  • Public Transportation
  • School buses

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Average Density of Virginia’s Metro Areas

Recently, I’ve been comparing a number of traits of metropolitan areas based on distance from the core.  Here I’m looking at the average densities of each metro area as you travel outwards from the center, calculated using census blocks and 2010 short-form census data.  I’ve graphed them in groups of three.  Cities with a strong core will have high densities on the left (near the center) that fall off as you travel outwards.  Cities whose densities fall off quickly on the right have clearer edges, while those that taper off slowly are more spread out.  Click on the graphs to view them full screen.

First are the three major metro areas.  Note that the Northern VA graph includes only Virginia census blocks, not the rest of the DC area.  Northern VA has the largest population by far, with fairly high densities even several miles into the suburbs.  Richmond has the smoothest curve.  I used downtown Norfolk as the core for Hampton Roads, but the area’s polycentricity is obvious.

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The New Racial Dot Map

As our regular readers already know, I’ve been playing around with a lot of dot density maps lately.  Today, however, we are releasing something new I think you might enjoy even more.

We decided to rehash Brandon Martin-Anderson’s idea of plotting one dot for every person in the United States, but with an added twist.  The new Racial Dot Map is an American snapshot; it provides an accessible visualization of geographic distribution, population density, and racial diversity of the American people in every neighborhood in the entire country. The map displays 308,745,538 dots, one for each person residing in the United States at the location they were counted during the 2010 Census. Each dot is color-coded by the individual’s race and ethnicity.


The map is fully interactive so you can zoom into any neighborhood you wish.  You can read more about the map and how we created it here.


Dustin Cable is a Senior Research Associate at the University of Virginia’s Weldon Cooper Center for Public Service where he conducts research on topics that lie at the intersection of demographics, politics, and public policy.

Animating historical county boundaries and census data

Among those of us who love old maps, the good people at the Atlas of Historical County Boundaries project have digitized and uploaded historical information on the shape of American counties.  With this data one can animate how America’s political boundaries have changed since the founding of the Massachusetts Bay and Virginia Colonies.  The above video shows historic county boundaries from 1630 to 1910 (shortly after Oklahoma and Indian Territory joined to form the State of Oklahoma in 1907).  Please note these boundaries show the creation of government-defined geographic units, not necessarily where population is located.

Another great thing about this data is the level of detail available.  For instance, focusing on the monumental changes that Virginia has gone through is quite interesting:

Note the emergence of many of Virginia’s Independent Cities at the turn of the 20th Century.

Things get more interesting when these county files are merged with historical census data.  Inspired by our previous post on “Every person gets a dot,” I decided to look at county population dot densities from the first United States Census of 1790 to the recent 2010 Census.  Here, every dot represents 5,000 people:

Dustin Cable is a Policy Associate at the University of Virginia’s Weldon Cooper Center for Public Service where he conducts research on topics that lie at the intersection of demographics, politics, and public policy.

Viable electoral college reform?

Artist Neil Freeman published a map of the United States redrawn to have 50 states with equal population, an art project that addresses what he says is “the fundamental problem of the electoral college”: “that the states of the United States are too disparate in size and influence.”

Fifty States with Equal Population

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How close are we, really? Population densities in U.S. Cities

In a previous blog post I talked about a new report from the Census Bureau on patterns of population change in U.S. metropolitan and micropolitan areas from 2000 to 2010. My previous post covered Chapters 1 and 2 of the report, which talk about the basic characteristics of metropolitan areas and give an overview of the population change over the last decade.

In today’s post I’ll talk about Chapter 3, which covers population density in the U.S. Population density tells us about the concentration of people in residential areas.  From this measure we get an idea of how closely people live to each other.  In this country, population density varies from more than 100,000 people per square mile in places like New York to just over zero people per square mile in places like remote Alaska.

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