Visualizing the cost of health care

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This chart, which was published by National Geographic in 2009, illustrates the costs and results of medical care in different countries.

The left side of the chart shows where the country stands in per-person spending on health care, in relation to average spending.  The right side of the chart shows where the country stands in life expectancy at birth, in relation to average life expectancy.  An upward-sloping line indicates citizens of a country are getting good value for their medical care spending; a downward-sloping line indicates the opposite.  The thickness of the line shows the number of doctor visits the average person makes in a year, a rough measure of the amount of medical care.

This type of chart was invented by Edward R. Tufte, regarded by many as the world’s leading expert on graphic presentation of information.  He put one in his 1983 book, The Visual Display of Quantitative Information, but it never caught on.

Many commenters on the National Geographic web log criticized the chart.  Oliver Uberti, who made the chart, responded by presenting the same information a different way, as shown below.

The greatest infographic ever drawn

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Edward Tufte, author of The Visual Display of Quantitative Information and Envisioning Information, wrote in the former book that this chart, drawn by the French engineer and civil servant Charles Joseph Minard in 1861, “may well be the best statistical graphic ever drawn.”

I’ve admired Tufte and his work for decades.  You can’t understand the contemporary world without understanding statistics, and, as W. Edwards Deming said, no number means anything unless it can be meaningfully compared with something else.  Where statistics are concerned, a good graphic is worth a thousand words of text – provided the graphic presents the information understandably and without distortion.

The graphic above on Napoleon’s retreat is a great example of how to do it.  At a glance, you can see the position and size of Napoleon’s army on the map at any given date, and how it dwindled as it advanced, then retreated.  A second glance, at the line on the bottom, shows the temperates on the dates during the retreats.

I read Tufte’s first two books in the 1990s, when I worked for Gannett newspapers, which were a pioneer in presenting graphic information, and I recommended them to everyone who would listen to me.  I still recommend them to all newspaper editors, graphic designers, technical writers and individual citizens who want to avoid being misinformed.