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Papers such as the Daily Express and Daily Mail do this all the time. They do. Unfortunately all the media do it. Even respectable papers do it, the broadcast media do it, even that bastion of careful reporting, the BBC, does it. They all cheat.

It’s not simply a question of editorial stance. That simply skews the interpretation of the facts, and we all sort of expect that and factor it in. What I’m talking about is deliberate misrepresentation of data. You’re exposed to this on a daily basis, and unless you’re a scientist you won’t bat an eyelid about it. Even if you are, you may miss it if you’re a bit lackadaisical.

I can hear the groans. Just what is the idiot savant on about now? I’ll tell you. It’s a crime that in scientific circles is much despised and vilified. It’s called suppression of the zero. You are a victim of this crime every single day of your life, and you probably don’t even notice. I do notice, and it infuriates me.

Suppose you want to draw a simple graph that shows how something changes with, say, time or distance or some other variable. You make the y  axis, the vertical one, show the value you’re interested in, and the x axis, the horizontal one, show the changes you’re subjecting the y value to. You’ve all plotted a graph I’m sure. You know how it works.

To make things as accurate as possible, and to show trends that are easily interpreted, you make both axes as big as the graph paper will allow. That’s obvious, no? The bigger the visual variation the better. Plus it means you don’t have to fret about the way a blunt pencil will obscure something subtle that a sharp pencil might reveal.

Something else you do, if you have any scientific integrity, is have the point where the two axes intersect the zero point for both values. It’s not hard to do this. If you do it properly, then you get a really accurate picture of what’s going on. With me so far? Goodoh.

The media are heroically inept at this. Probably nowhere is this better illustrated than in the way they report changes in stock market values. Anybody got stocks and shares? Ever been really spooked by the frightening looking graphs when some catastrophe wipes the value out of the stock market? Well just calm down, dear.

Say the Dow or FT indices are at 10,000 at the start of trading. There’s a natural disaster somewhere, and the stock market loses 3%. I’ll come onto this phenomenon in another post, but for the time being you’ll all have heard this sort of thing reported.

Now 3% isn’t that big, is it? It’s a bit ‘Ooops. Oh well. Ho hum.’ In the cosmic scheme of things it’s a blip, or what we call background variation. If you thought you had a quid in change in your pocket, did a recount and found you only had 97p, you wouldn’t lose any sleep would you?

Now if you’re the media you want to make this mere bagatelle look a big deal. To do this you draw a graph, and you do not, under any circumstances, start the y axis at zero. You start it at, let’s say, 9950. This is a despicable practice, the suppression of the zero, and in right thinking circles is likely to get you burned at the stake. Because now a tiny change in absolute value looks horrifically big. Zoot alors! That’s bad! Get the troops ready for rioting in the streets.

It’s not as bad as the media would have you believe, and if you doubt me, take a few minutes and run the experiment of plotting a graph of stock market values over a few days, and don’t suppress the zero on the y  axis. Plot the absolute values. However big you make the scale, the day to day variations will be miniscule. Tiny. The thickness of a pencil line. Nowhere near the vicious peaks and troughs that you see every day in the media. At the same time, plot another graph with the percentage changes on the y axis. Be good boys and girls and make that axis as long as the paper allows, and have the bottom value as 0%. It doesn’t look too dramatic then, either, now does it?

You may think this is not important, that suppressing the zero is no cardinal sin. Oh really? Well it will be when your pension fund disappears for no good reason, but simply because some bloke in braces and a stripy shirt spends all his working life looking at misrepresented data. It’s your future they’re buggering about with.