Using statistics to lie, and why democracy needs statistical literacy

Posted on 08/03/2012 by


I have often argued that we should encourage more statistical literacy in school and society in general.  This is not just because I am a statistics nerd.  Statistics is a language just like English; you can use it to describe the world, to clarify and the generalize.  You can also use it to lie or manipulate, and today I came across something that just made me cringe.

I want to take a moment to consider this bar graph.  Now, I’m not a particularly huge fan of Fox News as it is, but this is just such a perfect example of using visual statistics to manipulate that I can’t help pass some judgement on them.  Take a look at it: the vertical scale is from 34% to 42%, showing a difference of of only 4.6 percentage points.  That’s maybe a 13% change, but on this scale it appears to be a change of nearly 60%*.  Come on.  For comparison sake, I provided my own rudimentary graph of the same data:

Hmm…looks a bit different.  I have suggested before that graphs and data tell a story, and, as in verbal language, that story can be used to deceive and manipulate.

Some may point out that I am guilty of the same deception in my own work, and I accept that.  We present data in certain ways in order to make a point, and at times I have fallen into the trap of presenting objective data in ways that supports my argument.  But I am not calling for some sort of regulation of statistics or for heads to roll at Fox.  What I am calling for is better education in statistical literacy in order to give people the skills to determine for themselves whether the story the data is telling is valid.

I think this is so important, in part, because in this data-saturated point in history, democracy relies on a populace that can make inferences and decisions about data for themselves.  Democratic institutions demands citizens who can identify and articulate their needs, and who can make informed decisions about their political body.  In an age where we have more access to data than ever before, the danger that it is abused is also greater.  As a teacher, I strongly believe in giving every student the tools they need to be democratic citizens, and I don’t think it is hyperbole to say that the future of our country is at stake when it comes to statistical literacy.

Although the Fox News example is trivial, it points to something much larger, and something that we need to take seriously.  That is why I am so sad that the the Statistical Teaching, Aptitude and Training Act of 2011 (aka H.R. 1817) is stuck in committees and likely to never pass (read more about it here).  It would open up money for institutions to start statistical literacy programs, and provide resources to make statistics a larger part of the K-12 curriculum.  However, and I don’t mean to sound cynical here, I think that a confluence of factors, including big-money interests that see little value in education–especially education that would create better-informed citizens–will ensure that this and similar efforts will fail.  If Canada is any indication, this sort of effort is a long-shot in the US.  Recently, the very popular StatsCan program, which provided tools for educators to show how math applied to the real world, was axed during budget cuts.  I guess it is up to the teachers to make sure our students are prepared (as a side note, I would bet there is a correlation between math literacy and standard of living.  Just saying).

*(Edit: in other words, there is a difference of 4.6 percentage points between the numbers, which is a 13% change from the first to the second.  This is portrayed or amplified to look like a 60% change because of the scale they chose).