13 Mar Big Mac v. salad – feedback (updated)

Contrarian reader Ken Clare thinks Contrarian’s standards slipped with our post of a chart comparing US food subsidies:

Edward Tufte, the “Galileo of Graphics” you introduced us to back in June, refers to images like these as “chartjunk.”

I haven’t taken the time to measure the images you copied (from a committee of physicians who may have had a passing relationship with math sometime in their pasts), but the subsidies pyramid eyeballs closer to a 100-to-1 ratio than the 75-to-25 ratio it is labeled.

Update: A Diligent Reader award goes to Contrarian’s insomniac friend Alistair Watt, who spent time with a ruler and a spreadsheet before concluding that the front faces of the pyramid graphs were a nearly perfect match for the data they purported to represent, but their transformation into three-dimensional pyramids distorted the data severely.

In other words, had this been presented as a column chart or a pie chart, it would have been reasonable. However, when I laboriously calculated the volumes implied by each subsection, the results were dramatically different.