Ranking airlines: no easy task

Reader Joel D. submitted this chart showing airline revenues of major airlines around the world, another chart that puts bubbles on top of a map.  

Joel said:

Cool, but really quite naughty. Take the different size bubbles of British Airways (12.8) and Air France-KLM (29.7). Grossly disproportionate. I appreciate the designer's attempts to introduce a geographic element to this but the immediate take-outs here from the bubbles are misleading. 

Sometimes a bar chart is all life needs.

I think it fails all three facets of the Trifecta checkup: it does not have a well-defined practical question; the data is not processed properly; and the chart type does not work with this data.

• Most airlines are multinational companies that make substantial revenues outside their home countries... so the locations of their registered headquaraters are irrelevant. What is the question being addressed? It would appear to be where are the headquarters of the largest airlines in the world? I don't think this is an especially engaging question. What might be more interesting, for example, is the split between domestic and international revenues for different airlines, or the split among airlines of the revenues within each continent.
• Besides, the aggregate revenues data is not very useful for comparison purposes.  It ignores the  population... a circle in an European country is in reality much "larger" than a circle of the same size in China!  Because $200 million on 2 billion people is very different from $200 million from say 50 million! The right base for this data is probably something like revenue per passenger or passenger miles.
• The inclusion of Fedex also must be thought through thoroughly. I'd imagine that all the large airlines of the world also have freight divisions, and if we really want to address both passenger and commercial air revenues on the same chart (with which I don't agree), we should at least break out the freight revenues.

Comments

[Naomi B. Robbins]

Joel D. "Grossly disproportionate." The problem may be that the designer made the diameter of the bubbles proportionate to the values even though it is the areas of the bubbles that we visualize. This is a very common error.

[Joe Lotz]

Just a quick note, the Trifecta link is broken. Love the blog!

[Flights]

Misleading in many ways.

Revenue in the airline industry has little to do with profit.

Some with big revenues have huge losses.