Friday, November 30, 2012

Data link roundup (week of November 30, 2012)

The week's top data analysis links...


The Economist magazine posted its data analysis Advent calendar. Each day a new "most popular chart of the year" will be revealed.


It has long been suspected that the cultivation of potatoes played a starring role in the demographic transition by increasing nutrition and extending life expectancy. New estimates suggest that a quarter of "Old World" population growth from 1700 to 1900 can be attributed to the tuber.
Source: Library of Congress

TO SECEDE OR NOT TO SECEDE? (Actually, that's not the question...)

Despite widespread media hype about the post-election secession movement, and reports of nearly a million signatures collected across 60 petitions filed on the White House website, careful analysis of the data show that many of the signatures were the result of single individuals signing multiple petitions.

Once duplicates were removed, only 0.1% remained (about 300,000 signatures in a nation of more than 310 million people), according to results published by Neal Caren at UNC Chapel Hill.


Things on a university website:
Source: xkcd

Wednesday, November 21, 2012

Facts about the Thanksgiving feast

Facts and figures for the fourth Thursday in November...


43.6 million Americans (about 14 percent of the total US population) will travel at least 50 miles from home over Thanksgiving weekend. This represents just under a 1 percent increase in total holiday weekend trips, compared with 2011, and is the fourth consecutive year of increasing holiday travel, according to a report released by AAA.

Auto travel accounts for the lion's share (90 percent) of those trips. Despite notoriously long lines at the airport, only 8 percent of holiday travelers plan to fly, and the remaining 2 percent will travel via train, bus, or other mode.

About half of long-distance travelers (those going 50 miles or more) will make a day trip of it. The other half will spend an average of three nights away from home.

Despite increased travel, people plan to spend less, with estimated travel costs ringing in just under $500 per traveler in 2012 compared with just over $550 the prior year.


The average American consumes 13.3 pounds of turkey each year, according to data from the U.S. Census Bureau.

American farmers have raised about 250 million turkeys in 2012, with six top turkey-producing states accounting for nearly two thirds of the total.

With respect to traditional American Thanksgiving side dishes, U.S. growers produced more than 384,000 tons of cranberries, 550,000 tons of pumpkins, 672,000 tons of green beans, and a whopping 1,350,000 tons of sweet potatoes in the past year.

That said, even with a large domestic crop of sweet potatoes, the United States still imports $5.6 million dollars worth, or nearly half of all imported sweet potatoes, from the Dominican Republic.


Thursday, November 15, 2012

Geography Awareness Week: Waterfront Property

This week we'll be celebrating Geography Awareness Week by highlighting unique spatial visualizations of data.

Image source and source notes: Counties are based on 2010 geography and historical populations are based on population estimates derived from decennial census data (1790-2010).
Point locations are based on population-weighted county centroids.
According to NOAA, today more than half of the U.S. population lives in a coastal county. Recent graphics from the U.S. Census Bureau put the proportion closer to one third.

Why are the two measures so different?

The answer is in how you define "coast."

The Census Bureau analysis, pictured above, defines a "coastal county" as any county in which a portion of the county's boundary is adjacent to an ocean. NOAA's analysis includes the Great Lakes in the definition of coastal. Densely populated areas, like Chicago, account for the difference in the two measurements.

Wednesday, November 14, 2012

Test your geography knowledge

This week we'll be celebrating Geography Awareness Week by highlighting unique spatial visualizations of data.

In honor of GIS Day, the highlight of Geography Awareness Week, I have a three geography games to share:

Test your knowledge of the states in the United States by placing them (correctly) on the national map:

Or go abroad and play one of the many geography games at Lizard Point maps which range from naming European capitals to identifying the provinces in Afghanistan and identifying the nations in South America.

And last, but not least, is The World's Geo Quiz Challenge from Public Radio International.

Please feel free to share your score(s) in the comment section!

Happy GIS Day!

Tuesday, November 13, 2012

Geography Awareness Week: Election Coverage

This week we'll be celebrating Geography Awareness Week by highlighting unique spatial visualizations of data.

The 2012 election was marked by punditry, partisanship, and polling. But the election also allowed geo-spatial patterns a moment in the 24-hour news cycle spotlight.

Here are few striking visualizations from the election coverage:
Dr. Vanderbei at Princeton looks at changing patterns in party preference in presidential elections since the 1960s. Blue represents Democrat counties, red represents Republican, and green is all other.
Election results in 2012
Image source

Similarly stunning are the New York Times interactive graphics of the election results, which represent factors ranging from the size of each candidate's lead to the shift in votes between 2008 and 2012.

Taking the visualizations in a different direction, the population weighted cartograms published at the University of Michigan are pretty neat. They show a nation much less divided than the to-scale red-state/blue-state maps do.

Sadly, a flurry of racist tweets greeted the election results. The southeast had the highest proportion of racist tweets as a share of overall tweets on election night, as measured using a location quotient ratio.
Image source

So we have evidence that the United States is a very divided nation...
... or is it?
Image source

Sunday, November 11, 2012

Geography Awareness Week: Charting population density along America's highways

This week we'll be celebrating Geography Awareness Week by highlighting unique spatial visualizations of data.

The U.S. Census Bureau produced a series of graphics that show population density along some of the nation's most and least heavily populated transportation corridors.
Image source and source notes: Population density is based on average population density within 5 miles of the highway, in 2-mile increments, using 2010 block group centroids and 2010 Census population counts.
According to the Census Bureau:
Running from Los Angeles to Jacksonville, I-10 passes through 8 states and several major cities and traverses the 3rd largest population among the country's interstate highways. Population density within 5 miles of the interstate show several lengths with very low population density, including stretches between El Paso and San Antonio. Selected cities along the route are labeled, for reference, with cities of 250,000 or more shown in bold and with filled circles.
For comparative purposes, the Census Bureau provides a similar population density chart for the I-90 corridor, which runs along the northern part of the United States from Seattle to Boston. The highway, despite connecting Seattle, Chicago, and Boston, passes through some of the least densely populated areas in the nation.

Friday, November 2, 2012

Link roundup (week of November 2, 2012)

The week's top data analysis links...


Sally Raskoff, in her post titled "A Tasty Correlation" explores news headlines touting the correlation between chocolate consumption and Nobel Prize winners. (If only it were that simple!)

Using the chocolate example, Raskoff illustrates the difference between correlation and causality in an easy-to-understand summary of one of the basic principles of statistical research. The article would be a useful reading assignment for introductory Statistics or Sociology students.


The New York Times, as usual, provided beautiful and informative illustrations of the magnitude of damage left in the wake of hurricane Sandy.
Source: New York Times
A more detailed screen capture of the power outtages can be seen on FlowingData's post.

Thursday, November 1, 2012

Dia de los Muertos: Life expectancy trends

Historic New England cemeteries are a bit different than cemeteries in many other states in the U.S. in that they were often family plots, on local farms or homesteads, and not in a church yard.
Early Puritans rejected churchyard burials as they rebelled against other "papist" practices, as heretical and idolatrous. Instead, many 17th century New England towns set aside land as common community burial grounds. Headstone images from this period also reflect the rejection of formal Christian iconography in favor of more secular figures, such as skulls representing fate common to all men.
Source: National Park Service
As a result, a hiker often stumbles across tombstones on a typical trek in southern New England. These tiny graveyards provide a tangible record of the region's demographic history.

One of the most striking details, aside from the sizable share of persons who passed away before their fortieth birthday, was that so many tombstones were marked in years and months. In some cases, life was marked in years, months, and days.
Aged 23 years 10 months & 25 days
This is clear physical evidence of a phenomenon clearly understood by demographers: life expectancy was short at the turn of the last century.

There is, too, the startling reminder of high infant mortality in the 1900s New England. One in ten children did not survive to reach their first birthday.
Infant: age 3 months & 3 days
Pregnancy was also a dangerous condition. According to the CDC, "For every 1000 live births, six to nine women in the United States died of pregnancy-related complications." Today those trends have been sharply reversed. Across most populations infant mortality claims fewer than 7 deaths per 1,000 live births, and maternal mortality has declined to 0.1 per 1,000 life births.

But despite these dark statistics, the gravestones mark the longevity of many people who buck the trend.

Demographically speaking, life expectancy is just an average. Some people live far longer, and some much shorter. But the real life outliers are always a pleasant surprise.
Age 74 years 4 months & 20 days
Here is the life-expectancy data behind the anecdotal, archaeological evidence:
*Note: Data for 2010 reflect published 2009 statistics
To ensure comparable data over time, the chart above shows life expectancy for white males and for white females, at birth, from 1900 - present. Life expectancy in 1900 was lower than 50 years for whites, both men and women in the United States. Available evidence suggests that life expectancy was even shorter for minority populations (approximately 32 years of age for black men, and 33 for black women in 1900).