Greater Greater Washington

Posts about Demographics


Androids for the east side, iPhones for the west

Where do people use iPhones, Android phones, Blackberries, and other devices? In our region, it appears Android is far more popular on the east side of the region than the west:

Tweets from iPhones are in red, Android in green, Blackberry purple. Image from MapBox.
Click to toggle: All devices  iPhone only  Android only

Tom MacWright, who has written for Greater Greater Washington about open laws, made the tool for MapBox using 280 million Tweets, each of which has information about which kind of device the tweeter was using.

I initially expected to see a big blob of purple (Blackberry) in the federal core, but there is none; probably this is a combination of many federal agencies moving to iPhones, and federal workers not using their government phones for tweeting.

But really, these maps look awfully similar to the same maps of DC's demographic divides:

Left: Race and ethnicity. Image from Wikimedia. Right: College degrees. Image by Rob Pitingolo.

Update: Several commenters noted that the combined map seems to overlay iPhones over Androids, so green areas are really areas with Androids but fewer iPhones. I've added a toggle to switch between the combined map, iPhone-only, and Android-only.


Election results maps show persistent geographic divide

Keith Ivey has created an interactive map of DC's April 23 special election results. The maps seem to back up the notion that there are ongoing geographic and racial divisions in our politics, though except for east of the Anacostia (which is a big "except"), Elissa Silverman's appeal was far broader, geographically, than citywide candidates in other recent elections.

Vote share for Anita Bonds (left), Elissa Silverman (center), Patrick Mara (right).

Ivey also maps which candidate won the most votes in each precinct.

Left: Plurality votes on April 23, 2013. Bonds=cyan, Silverman=red, Mara=blue, Frumin=green. Right: Plurality votes on April 26, 2011. Orange=orange, Biddle=red, Mara=blue, Weaver=green. Images by Keith Ivey.

Ivey also notes that looking at the overall amount of ink for each candidate doesn't necessarily reflect reality. The peripheral areas where Bonds was strongest, for instance, are also less densely-populated areas of the city. He says,

The map can be misleading in the same way typical U.S. presidential election maps are, since the area of a precinct is not proportional to the number of voters there. A candidate who wins in densely populated, high-turnout areas will often look worse on the map than a candidate who wins in less dense or low-turnout areas.
One observation is that you can't really detect Rock Creek Park on the Silverman map. Rock Creek forms a bright line on the other maps, but not Silverman's. On the other hand, the Anacostia River is a bright line on everyone's map.


What counties are larger than whole states?

We know that DC has more people than Wyoming and about to pass Vermont. Reddit user desert_wombat created a map of all US counties that are more populous than some states.

With 9.8 million people, Los Angeles County is larger than North Carolina, the 10th most populous US state. (It's also geographically larger than Rhode Island and Delaware, combined).

Baltimore County (which doesn't include Baltimore City) is more populous than Wyoming, Vermont, North Dakota and Alaska; Prince George's is also larger than South Dakota; Montgomery County larger than Delaware; and Fairfax County has more people than all of those as well as Montana and Rhode Island.

Thanks to Dan Malouff for the tip via Twitter.


Compare the neighborhood density of US urban areas

Last week's post about census tract density in the DC area showed which neighborhoods inside the Beltway are densest. Now let's look at the densest spots in the core areas of other large cities.

Urban areas are defined by the US Census as geographically-connected areas with a population density of at least 1,000 people per square mile (ppsm). The standard provides a uniform definition of "city," more useful for national comparisons than political boundaries. These maps show the central county in each of America's 20 largest urban areas, in order beginning with the largest.

1. New York: America's biggest city breaks the scale. While others on this list might have a few neighborhoods in the top density category, New York is covered end to end. It's one of only 4 cities with tracts above 100,000 ppsm. Its peak is 200,000 ppsm.


2. Los Angeles: Despite its reputation for sprawl, LA compares favorably to the densest cities after New York. Its peak density of 94,000 ppsm is well above DC's.


3. Chicago: Home to probably the single densest census tract in America, a 508,000 ppsm anomaly that's so small it's not visible at normal scale. Besides that tract, Chicago tops around at about the same level as LA.


4. Miami: Thanks to more narrowly-drawn census tracts along its high-rise coast, Miami's peak density shot up from 38,000 ppsm in 2000 to 77,000 ppsm in 2010, but the actual change wasn't as significant on the ground.


5. Philadelphia: At 64,000 ppsm, Philadelphia's peak is about the same as DC's, but Philly's rowhouse neighborhoods extend farther out.


6. Dallas: Dallas' density dropped significantly. It has fewer dense tracts in 2010 than in 2000, and its peak is down to 44,000 ppsm from 57,000 ppsm.


7. Houston: Unlike Dallas, Houston appears to be densifying. Oddly, its densest area is not the core.


8. Washington (with Arlington & Alexandria): Washington is has more dense neighborhoods and a higher peak than in 2000. The numbers shown on these maps are slightly different than those on Michael Rodriguez's map, which used a different map projection to calculate area. These census numbers are official.


9. Atlanta: Not only is Atlanta shockingly sparse, its densest tract fell from 41,000 ppsm in 2000 to just 21,000 ppsm in 2010. The explanation? A downtown public housing complex was demolished, erasing the population of the densest 2000 tract.


10. Boston
One of only 4 cities with a tract above 100,000, Boston has a single tract that reaches 110,000 ppsm.

2000: 2010

11. Detroit: Detroit's peak density of 18,000 ppsm is about the same as in 2000, but the number of mid-density tracts in the 10,000-20,000 ppsm range declined significantly as the city continued to empty.


12. Phoenix: Central Phoenix didn't change much, and tops out at 23,000 ppsm.


13. San Francisco: San Francisco has more tracts above 100,000 ppsm than any city except New York. It tops out at 161,000 ppsm.


14. Seattle: With a peak of 51,000 ppsm and a small but significant core, Seattle occupies a middle ground between the older denser cities and newer sparser ones.


15. San Diego: While downtown San Diego densified compared to 2000, and its 50,000 ppsm peak is higher, some of its other denser neighborhoods are sparser in 2010.


16. Minneapolis: Minneapolis' changes were minor compared to most other cities. Its peak was 25,000 ppsm in 2000, and it still is in 2010.


17. Tampa: By far the sparsest city on this list, Tampa's peak of 13,000 ppsm means it has no tracts in the 3rd or 4th categories, and precious few crack even into the 2nd.


18. Denver: Like a smaller Minneapolis, Denver looks much the same. Its peak of 23,000 ppsm is respectable for a mid-sized non-coastal city.


19. Baltimore: Baltimore's lone tract in the densest category is an impressive 86,000 ppsm, but that tract is down from a whopping 176,000 ppsm in 2000. What happened?


20. Saint Louis: Saint Louis' losses have been less drastic than Detroit's, but they still hurt. Its peak is down to a Tampa-like 13,000 ppsm, from 15,000 ppsm in 2000.


I made all these maps using American FactFinder on, which has data for every county in the United States. I couldn't have done it without Geoff Hatchard, who walked me through the laborious process. If you'd like to make your own maps, I documented step-by-step instructions. Godspeed.

Cross-posted at BeyondDC.


Logan Circle overtakes Columbia Heights as densest in region

Density is a good thing for urbanism. More density means more shops and amenities nearby, better transit service, and shorter walks. But what qualifies as dense? Overall city density is often reported, but a more telling statistic is neighborhood density.

Thse two maps show DC neighborhood density at the time of the 2000 census (top) and 2010 census (bottom). I made the 2000 map using sometime after the 2000 census. Michael Rodriguez created the bottom map just recently. Unfortunately the two maps use different scales, but they're still informative.

In 2000 the densest census tract in the DC region was in northern Columbia Heights, between Spring Road and Newton Street. It had 57,317 people per square mile (ppsm). In 2010 that tract is up to 59,209 ppsm, but that's only good enough for 2nd place in DC, and 3rd regionally.

The densest tract is now southern Logan Circle, between Rhode Island and Massachusetts Avenues. It's boomed and is now a whopping 67,149 ppsm.

The rest of central Northwest, from Mount Pleasant down to Massachusetts Avenue, varies from around 30,000-50,000 ppsm. Capitol Hill is in the 20,000-30,000 ppsm range.

Meanwhile, in Alexandria, the tract at the corner of I-395 and Seminary Road is up to 59,886 ppsm, 2nd densest in the region after Logan Circle. There hasn't been any new development in that tract since 2000, but the suburban-style apartment towers in it may have fewer singles and more families, which could account for the increase. Crystal City is 45,448 ppsm, and Ballston is 43,788 ppsm.

Suburban Maryland's densest tract is in Langley Park, at 49,354 ppsm. Downtown Silver Spring is 34,816 ppsm, and downtown Bethesda is around 11,000 ppsm.

Cross-posted at BeyondDC.


What if "inside the Beltway" were a city?

If "Inside the Beltway" were a city, how would it compare to other major cities? It would be almost the size of Los Angeles but half as dense a little larger in area than Chicago but less dense than Los Angeles.

Image by Michael Rodriguez. Click for interactive version.

The latest Census data show that Montgomery County reached 1 million people, a statistic that has gotten a lot of worthy attention. Still, let's remember that jurisdiction boundaries are pretty arbitrary. As commenter AlanF also pointed out, DC, Arlington, and Alexandria (the "core jurisdictions") have just about reached 1 million as well (999,662 as of the latest Census estimates).

Michael Rodriguez decided to analyze "inside the Beltway" as if it were its own city. Given the way the Beltway separates communities, it's a good natural boundary and means more than the artificial lines between counties or between DC and Maryland.

Inside-the-Beltway would have about 1.7 million people. in 423 square miles. That's a little smaller than Los Angeles and only about half the density of people per square mile.

Update: Commenter npm points out that Rodriguez's table appears to be incorrect, and "Inside the Beltway's" density may be more like 80% of Los Angeles' rather than 50%.

Table by Michael Rodriguez.

Update 2: A reader with access to GIS systems has estimated the land and water area of "Inside the Beltway." Plugging in those numbers, and assuming that the other numbers on the table are correct, the table would look like this.

Update 3: Rodriguez has updated his post and fixed the errors in the DC and "Inside the Beltway" numbers. I've updated the table to reflect them.

GeographyTotal area
(sq. mi.)
Water area
(sq. mi.)
Land area
(sq. mi.)
(Pop./sq. mi.)
Inside DC Beltway266102561,725,6866,749
District of Columbia68761632,32310,298
New York City4691663028,336,69727,541
Los Angeles503344693,792,6218,087
San Francisco23218547805,23517,177
Click on a column header to sort.

The lower density than Los Angeles comes because most of the land inside the Beltway is actually not very dense, except for central DC, Capitol Hill, along Georgia Avenue, the Rosslyn-Ballston corridor, bits of Silver Spring and College Park, and a few other places.

Density by census tract. Image by Michael Rodriguez. Click for interactive version.

Also, if "inside the Beltway" were a city, metonymy in the national press would be even more severe than it is today.


Washington growing more at the center, less at the edges

After years of rapid population growth, greater Washington might be slowing down. However, the real story is where most regional growth is happening: in and around the Beltway, not on the fringe.

Revitalized inner-city and suburban communities lead regional growth. Photo by the author.

Yesterday, the Census Bureau released population estimates for the Washington-Arlington-Alexandria Metropolitan Statistical Area, which encompasses the District and 27 surrounding counties and independent cities in Maryland, Virginia and West Virginia.

While the Washington Post focused on slightly slower population growth than in previous years, there are much more interesting trends occurring.

Regional growth is still among the highest in the nation

The Census Bureau estimates that the region had just over 5.8 million residents in 2012. If you include Greater Baltimore (the Washington-Baltimore-Northern Virginia Combined Statistical Area), the larger region has 8.6 million people, making it the fourth-largest metropolitan area in the country, behind New York, Los Angeles and Chicago.

Greater Washington added 89,000 new residents between July 2011 and July 2012, which the Post notes is fewer people than we added the year before. It calls this the "twilight hour of a remarkable phase in the Washington region" during which Americans flocked to the area in search of jobs, adding to the area's population. Yet we've still had the fifth-largest increase in population of any metropolitan area in the country. We added more people than traditionally fast-growing Sunbelt cities like Atlanta and Phoenix.

Inside-the-Beltway communities among the nation's fastest-growing

Our region is also home to several of the nation's fastest-growing counties and independent cities, notably the District of Columbia, which after decades of population loss is now growing rapidly. It's now the 61st fastest-growing "county" in the United States, having grown by 5.1% and adding over 30,000 residents between 2010 and 2012.

The District now has 632,000 residents, about what it had during the 1980's. For the first time ever, Washington now has more people than Baltimore City, which has also started gaining residents for the first time in decades.

Joining the District on the list are several jurisdictions in Northern Virginia, including Arlington and Loudoun counties and the cities of Alexandria, Falls Church and Fredericksburg, which grew at a rate of 12.44% between 2010 and 2012, making it the region's fastest-growing community.

Places like Loudoun are no stranger to the list of speedily-growing counties, having transitioned from farms to suburbia in less than a generation. However, the addition of inside-the-Beltway communities like Arlington and Alexandria is impressive. DC, Arlington and Alexandria have all sought to encourage smart infill development around Metro as a way to revitalize older neighborhoods, and it's clear they've been really successful.

Meanwhile, first-ring suburban counties haven't been slouching. Between 2010 and 2012, Montgomery and Fairfax counties grew by 3.39% and 3.41%, respectively, just below the region's average of 3.98%. In 2012, Montgomery's population topped 1 million for the first time, making it and Fairfax the only jurisdictions in the region with a 7-figure population.

Majority of region's growth happening in and around the core

Not only are the core and inner-ring suburban counties continuing to grow, but they're carrying most of the region's growth. Of the 224,000 people who moved to Greater Washington between 2010 and 2012, 62% of them moved to the city and inner suburbs. As a result, the core and inner ring now contain 69% of the region's total population.

Roughly 1 in 7 new residents moved to the District of Columbia, while 22% moved to either DC, Arlington or Alexandria. Though the inner suburban counties, Montgomery, Prince George's and Fairfax, are growing at a slower rate than both the core and "second-ring" counties like Loudoun and Prince William, they received about 40% of the region's population growth. Another 30% occurred in the second-ring counties, while 7% went to rural counties in Maryland, Northern Virginia and West Virginia.

We don't have any data for where growth is specifically occurring in the inner ring, but judging from the building boom in places like Silver Spring in Montgomery and Merrifield in Fairfax, it's likely happening in the same kinds of places and for the same reasons as in the District, Arlington and Alexandria.

Growth is uneven

The largest Greater Washington communities by population.

Communities by share of regional population and population growth.

The region's fastest-growing communities.

While most close-in communities are growing at a fast clip, Prince George's County isn't doing as well. It grew at a rate of just 2% between 2010 and 2012, placing it among the region's slowest-growing counties. This is not only unfortunate for Prince George's, which for decades has lagged neighboring counties in drawing people and businesses, but for the region as a whole.

DC's resurgence and the continued growth of older suburban counties like Montgomery suggest that people want to live close in. Presumably, Prince George's should benefit from that demand, but for a variety of reasons it's being directed to farther-out areas, which results in more traffic, more destruction of natural or agricultural land, and the ongoing disinvestment of older neighborhoods. Directing more investment to Prince George's should be a regional priority, as it will further add to the strength of other communities around the Beltway.

Yes, Greater Washington is growing a little more slowly than it used to, and that's okay. The big news is that unlike many metropolitan areas in the United States, we're growing at the center, not at the fringe. Not only does it make our region stronger and more sustainable, but it shows that other places around the country don't have to accept unending suburban sprawl as a given.


Men are from Rosslyn, women are from upper Northwest

Aimee Custis sent along a great map from Trulia, showing the ratio of single (straight) men to single (straight) women across the region:

The Washington metropolitan area and "Bethesda-Rockville-Frederick," which the Trulia data breaks out separately, have the nation's highest ratio of women to men among the nation's 100 largest metropolitan areas.

The zip code with the most male-heavy singles is Rosslyn; the most female-heavy, upper Connecticut Avenue.

Trulia economist Jed Kolko writes:

Billy Joel was right: in most metros, the neighborhood with the highest ratio of men to women is in or near downtown, as well as in recently redeveloped neighborhoods. ...

The neighborhoods with the highest ratio of women to men tend to be more residential, like San Francisco's Marina and Seattle's Queen Anne, and more upscale (and safe), like the Upper East Side and Upper Connecticut Avenue.

What do you notice in the map?
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