Exception to the rule

It's pretty hard to decree hard-and-fast rules for graphical design; every rule seems to admit its exception.  This reinforces Tufte's contribution as he has successfully organized the rules in his collection of books.

Dustin J sent in this chart from the Economist.  Its first impression is ugly and overly complex.

Dustin commented:

Steven Few says not to use stacked bar charts because you cannot compare individual values very easily and as a rule I avoid stacked bars with more than six or seven divisions. What do you think of this stacked bar--I think it is quite effective in telling the story.

On this blog, I have also re-done some stacked bar charts but this one is truly an exception to the rule.  The reason why this one works is that it's not about the individual components, it's showing that the US consumes more than all those countries combined. 

If only it has the proper caption!  The Economist is uncharacteristically detached here: "Petrol consumption per day", "Litres bn, 2003".  How about "Goliath v. Davids"?  "US v. the World"? "Dream Team USA"?

It'd help if they tone down the colors; also, by simply annotating the total litres for the US and the total for the other countries, they would have made a clearer point without using gridlines.  But these are minor glitches in an otherwise effective chart.

Source: Economist, July 2007.

Comments

[Mike Anderson]

A minor nit, but the countries in the stacked chart aren't the same as those on the bar chart. I'm not saying that Turkey, Nigeria, and Turkmenistan would have put the stack higher than the US, but the chartmaker does have some numbers up his sleeve.

I'm OK with the gridlines; they let you eyeball estimate some of the individual countries...

I'm eager to see how the bars stack up in 2010.

[Matthew]

It's misleading, and I worked out why when i saw France apparently consumes less petrol than Australia. That doesn't sound right, and I believe it's because in France diesel-engined cars account for about 55% of the market. Similar in most European countries diesel is between 30% and 70%. So you can probably double Europe's share in that table.

So it's correct when looking at petrol/gasoline, but not if you are trying to make a point about use of oil-related products in automobiles.

[David]

This is total per day by country? Would a more accurate metric be per person by country?
On the right chart - as I recall, Iran subsidizes gasoline while the US and Europe tax it. http://www.iht.com/articles/2007/06/29/news/iran.php

[Scott Lamb]

I think the original is a good concept, though it's too bad that it doesn't include all fuel (Matthew pointed out this is just gasoline) and that the consumption and price numbers are from different years.

There are a few other graphs that might be interesting:

* fuel/population/timespan vs country (how does the average American's fuel use compare to the average non-American?)

* money/population/timespan vs country (how does the average American's fuel spending compare?) possibly rather than money in absolute terms, a percentage of income

* fuel/population/timespan vs money/fuel (is the US an outlier, or do people in general buy more where it's cheaper?)