February 17, 2014 § Leave a comment
Economists closely watch the quarterly change in gross domestic product as a sign of a country’s economic well-being. A contraction (aka negative economic growth) in GDP for two consecutive quarters is the technical indicator of a recession.
Here’s the catch: the U.S. and Eurozone calculate the quarterly change differently. If you want to chart the figures together one set needs to be recalculated.
The U.S. expresses its GDP figures as a quarterly change at a seasonally adjusted annual rate, or what the quarterly rate would be if it continued for four quarters. The Bureau of Economic Analysis does this to make it easier to compare a quarter’s rate to rates in previous years. The Wall Street Journal chart above is a good example.
The Eurozone expresses GDP as a straight change from the previous quarter, not at an annual rate. See the chart below from the National Post.
If you want to compare Eurozone GDP to U.S. GDP your best bet is to recalculate the Eurozone GDP at an annual rate. I’m not going to step you through it, since the BEA already does an excellent job of it at this link: http://www.bea.gov/faq/index.cfm?faq_id=122. You will need to get the quarterly GDP values (not the percentage changes) to make this calculation.
October 7, 2012 § 1 Comment
Shark attacks loom large in our imaginations even though the chance of being killed by a shark is infinitesimally small. Our obsession with shark statistics provides fodder for compelling charts, such as the classic infographic by the Ft. Lauderdale Sun-Sentinal shown above or the more sparse, image-driven chart below.
Visual journalists most frequently go to the International Shark Attack File at the Florida Museum of Natural history for shark-attack data. The site posts an annual report that includes trends by location and circumstance.
Here are some examples of terrifying details charted in the report.
Another source, the similarly named Shark Attack File, provides less analysis but greater detail on each shark-attack report.
Here’s an example from the National Post of how you can use these stats. The Post’s team created an icon for each recorded attack over the past 100 years.
August 18, 2012 § Leave a comment
As I post this, you don’t have to worry much about West Nile virus, unless you happen to live in Dallas County, Tex., where 155 people have caught the disease and 10 have died so far this year. I know this because the Centers for Disease Control and Prevention tracks West Nile virus closely and reports every case where it has been found in mosquitoes, birds, horses and humans.
The Wall Street Journal map above reflects data from the CDC that can be found on this Web page:
If you want to create a more local map or graphic, the CDC goes into greater geographic detail, as you can see from this map on the CDC West Nile virus pages.
July 9, 2012 § 1 Comment
Diffusion indexes confuse the heck out of people the first time they see one. But once diffusion indexes become familiar, they make a whole lot of sense. To chart a diffusion index and label it properly, you really need to understand what the numbers mean. (Okay, that goes for any graphic, but don’t expect to wing it with a diffusion index.)
With a diffusion index, 50 is the baseline, anything above that indicates expansion, anything below that indicates contraction. What confuses people is this: If the number is 60 in one month and 55 the next, that does not indicate contraction, it indicates slower expansion. If the number is 40 one month and 45 the next, that does not indicate expansion, it indicates slower contraction.
Take a look at the four examples of diffusion indexes in this post. I believe they were all made by Pat Minczeski on The Wall Street Journal graphics team. You will see that The Wall Street Journal took great pains to label not just whether a figure indicates expansion or contraction, but whether it is slower or faster than the previous month.
Usually when you chart a diffusion index, you are looking at some form of purchasing managers index of manufacturing activity. The Institute for Supply Management and Markit provide much of this data. To create an index, ISM surveys purchasing managers and asks them whether they’re doing more, less, or the same of things like placing new orders, hiring people or producing goods. The manufacturing index (or its sub-indexes) reflects their responses.
Here is a link to the most recent ISM report: http://www.ism.ws/ISMReport/content.cfm?ItemNumber=10748&navItemNumber=12949
And here are the historical numbers for the main manufacturing index: http://www.ism.ws/ISMReport/content.cfm?ItemNumber=10752
For detailed historical figures, you probably need to contact the Institute for Supply Management or Markit. I haven’t found detailed figures on their sites. Give me a shout if you come across them.
April 23, 2012 § Leave a comment
Each year, the Federal Aviation Administration counts up all the space launches around the world and releases a report with loads of detail on how many launches each country made, what they were for, and even the type of rockets they used.
Each report only gives information for the previous year, so if you want to show a trend over time, you would have to go through each annual report to gather the info. You can find them here:
The big takeaway from this year’s report is that China has passed the U.S. in the annual number of space launches for the first time.
I haven’t had a chance to use info from this report in a graphic, but I’m keeping it in my back pocket.