Fun With Charts: Scale Matters

At first glance, this chart makes it look like food stamp usage has gone from almost nothing at some unspecified time in the past, to some huge amount over a span of who-knows-how-long.
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Only a fraction of the visitors to the site will click on the chart to see the scale, which reveals that the increase is about 6% of the population over four years.

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While it’s certainly worthy debating whether a 6% increase in food stamp usage over four years is alarming, that figure doesn’t grab like the sharply-angled chart, which puts 8.5% and 26M as the lowest measurements, where our brain expects to see a baseline of zero.

Illinois rewarded for misspending only $52 million on food stamps « Watchdog.org.

One thought on “Fun With Charts: Scale Matters

  1. At one of the conferences I was at, I made a very specific point of mentioning that the chart they were showing us had been rescaled to minimize the visual effect. The plot was graphed on a logarithmic vertical scale – each tick upward was a 10-fold increase in the problem. I caught it as they were talking about the nice straight-line trend they saw…

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