Author Archives: Matt Stiles

I'm a data journalist at NPR. I try each day to create a data visualization, or I post those I find online. Let me know if you have ideas for future visualizations. Contact me: mattstiles at gmail.

Texas’ Looming Hispanic Shift Explained In 2 Charts

Quick post for work…


NPR is taking a look at the demographic changes that could reshape the political landscape in Texas over the next decade – and what that could mean for the rest of the country. Within a decade, Hispanics are projected to eclipse non-Hispanic whites as the largest race or ethnic group in Texas.

Read more at: www.npr.org

“Major Rulings Of The 2012-13 SCOTUS Term”

Kennedy is almost always in the majority. Interesting.


How often each justice was in the majority in divided cases over the last three terms. The court ruled that isolated human genes may not be patented. Association for Molecular Pathology v. Myriad Genetics The court ruled that a farmer violated patent laws by saving seeds from genetically modified soybeans.

Read more at: www.nytimes.com

“Grocery Store Geography”


I’ve been poking around grocery store locations, courtesy of AggData, the past few days. There’s a grocery store just about everywhere you go in the United States, because, well, we gotta eat. They look similar in that they sell produce on one side, meat in the back, and snacks and soda on the side opposite the produce.

Read more at: flowingdata.com

Mapping GeoJSON On Github

I’ve been hoping to tinker with Github’s new mapping service since the company announced it earlier this month. Turns out it’s quite easy. You just commit a GeoJSON file to your repo, and voilà.

The points on this simple map represents the location of each car2go I’ve rented (excluding those in Austin, Texas). Surprise, they’re mostly clustered in our neighborhood:

car2go locations

This is a simple as it gets. The service also allows other data types, like polygons, for example. Tomorrow I’ll try a more interesting data set, maybe DC property parcels or 311 calls locations. And I’ll experiment with the Github docs to see how I can customize the icons and design. We’ll see…

BTW: Github is using MapBox to create its custom map base layer. Read more about that here. And thanks to my co-worker, Chris Groskopf, whose csvkit suite makes it super easy to convert basic data files into GeoJSON.

Mapping 2012 Presidential Results in Majority Minority Counties

Yesterday I mapped the more than 350 “majority minority” counties in the United States, breaking them down by race and ethnicity groups and geography. As promised, today I’ve looked at how these counties (in the contiguous United States) voted in the 2012 election.

Obama won about 70 percent of these counties. Here’s the map:

The Daily Viz

The Daily Viz

That map, of course, can be misleading — as often happens in elections. That because the area of the counties can distort their actual voting power. In this case, Obama won more “majority minority” counties with urban populations and many more voters, such as Los Angeles (Calif.), Cook (Ill.) and Kings (N.Y.) counties, among others. Romney carried rural Republican counties, largely in Texas and the west.

Obama received nearly 18 million votes in the “majority minority” counties he carried. Romney got 2 million votes in his “majority minority” counties. In the end, Obama received a net 10 million votes from “minority majority” counties — nearly double his national margin over Romney in the country as a whole.

The map below uses proportional circles on top of the choropleth map above to help visualize the total votes in each county. You can see how Obama won in many of the most-populous counties, increasing his national margin (though not necessarily helping with the Electoral College — except in critical purple states he carried, such as Florida and Virginia).

The Daily Viz

The Daily Viz

You can download the data here.

For more updates, follow me on Twitter.

Mapping ‘Majority Minority’ Counties

This week the U.S. Census Bureau released updated national population estimates, including a list of the counties that grew most rapidly from 2010 to last summer. I wrote about these counties in a political context this week for work.

Included in the release was a note that six more counties had flipped to “majority minority,” as the bureau calls them. These are counties in which non-Hispanic whites represent less than half the population.

With those six, the country now has at least 352 counties — about one in 10 of the total — in this category. Here they are on a map:

The Daily Viz

The Daily Viz

These counties exist largely because because of the relative size of the Hispanic and black populations (though Hawaii and Alaska have high Asian population rates), depending on geography. Western counties have higher percentages of Hispanic residents, and counties in the Deep South have higher rates of black residents. Of course there are some exceptions sprinkled throughout the country.

This map shows the rate of “minority” residents by county:

The Daily Viz

The Daily Viz

This map shows the percentage of Hispanic residents by county:

The Daily Viz

The Daily Viz

This map shows the percentage of black residents by county:

The Daily Viz

The Daily Viz

You can download the data here. Tomorrow we’ll examine how these counties voted in the 2012 presidential election.

For more updates, follow me on Twitter.

Tracking Check-ins With Foursquare Time Machine

Location-based service Foursquare recently released a new feature allowing users to track their past checks by location, venue type and other metrics The browser app visualizes check-ins in sequential order, creating a colorful map and ultimately a personalized infographic.

Apparently, I’ve checked in on foursquare more than 2,400 times — so mine took a bit — but the end result is (slightly) interesting:

foursquare-the-next-big-thing

PREVIOUSLY: 

Mapping Smartphone Use By State

Today at work I wrote a quick blog post about a new U.S. Census Bureau report on Internet use in America. The report suggested that smartphones were helping decrease the digital divide of access to the Web among blacks and Hispanics.

The U.S. Census Bureau survey was the first time the agency asked respondents about whether they used smartphones to go online, allowing a comparison of each racial and ethnic group’s overall digital activity. The bureau said that whites and Asians were more likely to have access to a home Internet connection.

Asians, for example, reported home Internet rates that were 27 percentage points higher than Hispanics. That rate disparity dropped to 18 percentage points with smartphone and home use combined.

Close to half of all Americans use a smart phone to connect to the Internet, and that rate remains similar across all groups: Asians (51.6%), non-Hispanic whites (48.6%), blacks (47.3%), Hispanics (45.4%).

The report also examined smartphone use by geography, with some interesting results:

While many states in the Southeastern and Northeastern parts of the country (along with certain areas in the Midwest) had smartphone usage below the national average of 48.2 percent, the vast majority of states west of the Mississippi River had smartphone usage rates either statistically higher or not statistically different from the national average.

Screen Shot 2013-06-10 at 9.08.07 PM

Read the report, and download the data.

Birthday Heatmap Born Again

Last year on my birthday I created a quick heatmap visualizing birthdays by their rank on the calendar. Despite its flaws, the graphic went viral by The Daily Viz standards, receiving a quarter million views.

Most of the attention came in the month of May 2012. But what’s been interesting is its long-tail appeal. Every few months or so my traffic spikes — and I always know why. It has been viewed 100,000 times in the last year. This chart from Google Analytics shows the spikes, including one in recent days thanks to links from Radiolab and io9.

analytics

Last fall, around the time that birthdays are most common, my wife and I had a baby, Eva, and I’ve found it difficult to keep this blog “daily” while also focusing on my day job. I’m using this most recent traffic spike as inspiration to get blogging again.

I hope, someday soon, to create something that’s more popular than that silly heatmap. Stay tuned.

Follow me on Twitter for updates.