When visualizing numbers gets ridiculous

by July 18, 2011

Logo for Phillip Blanchard blog posts“The spotlight is on the government’s questionable fiscal behavior as it nears its borrowing limit of $14.3 trillion and confronts the risk of a crippling default.” (CNBC)

“Converting the debt limit into dollar bills stacked end to end is four times as high as the distance between the earth’s surface and the moon, a money trail that would wrap around the earth more than 39 times.” (Fiscal Times)

“Don’t help me.” (Max Bialystock to Leo Bloom in “The Producers”)

Big numbers are a big problem.

It is no insult to the readers that a number like $14.3 trillion is difficult to comprehend. Check that. It’s impossible to comprehend, no matter how many times it shows up in the news.

This Fiscal Times illustration purports to show a stack of dollar bills equal to the amount of the debt limit – $14.3 trillion – stretching four times the distance from the Earth to the moon.

It doesn’t help to calculate how high 14.3 trillion dollar bills would go. That is an insult, no easier to comprehend. If you think about stacking dollar bills to the moon and back, for example, you’re going to get bogged down in details like gravity or, for all I know, solar wind.  It also doesn’t help that these calculations vary wildly.

NPR did an interesting story recently about big numbers, but by the end, it goes back to the big pile of dollar bills. The math expert quoted, Keith Devlin of Stanford University, says:  “If you show someone, an adult person, up to seven objects, they will instantly be able to recognize how many there are. If the collection’s bigger than seven, we have to visualize them in groups, or we have to count them.”  That’s plausible. Yet a smart writer knows that a reader can neither visualize 14.3 trillion dollar bills nor count them.

This AP graphic said the amount of oil in the BP spill would fill 290 Olympic-size pools.

The technique of converting big numbers to supposedly understandable terms pops up everywhere.  Last year, the Associated Press went so far as to offer an online graphic that expressed the amount of oil spilled in the Gulf of Mexico in soda cans and Olympic-size swimming pools. Quick. How big is an Olympic-size swimming pool?

Even when numbers are perfectly comprehensible, we see condescending attempts to simplify them for the simple folk. In 2006, the Peoria Star Journal reported: “Glenn Theinert has donated enough blood to fill the average SUV gas tank three times, or nearly 747 soda cans.” One wag at the Testy Copy Editors forum noted that it was “enough soda cans to make up an airplane model number.”

The best way to understand how much blood someone has given is to express it in pints. What a concept.

Over the years, well-meaning writers and editors have argued with me about this ridiculous device.  They never got very far. My rule:

Express numbers in numbers. Readers do not have to “visualize” them, which is lucky, because they cannot.

Usually it’s enough to know that they’re really, really big.

None of this is to say that breaking down numbers is not occasionally helpful. For example,  it might be worth reporting that a CEO’s salary is 125  times the pay of an average company employee.
Expressing national  debt as a percentage of gross domestic product is useful. But these devices  do not require imagination — and that’s good.