Statistics are integral to political debate. Politicians use them all time and sometimes abuse them.
One of my favourite examples was Labour's use of 'average' Council Tax bills in the 1990s: although the average Labour council charged higher bills in each and every Council Tax band, Labour figured out that the average bill in their areas was lower - nothing to do with councils' spending decisions, purely because property prices were lower in Labour areas and hence they had a higher proportion of the properties in the lower Council Tax bands - and that they could use this to create a completely misleading impression.
Most of these statistics make no impression. But sometimes you hear a statistic that transforms how you see an issue. I had one such experience this morning.
I was reading Conservative Home and noticed an article by my former boss, Greg Clark with the headline:
"The UK economy, excluding the financial and North Sea sectors, has grown by over 4½ per cent in real terms since the beginning of 2010".
"So what?" you might say. "The economy has barely grown since 2010, what does it matter how particular sectors are doing?"
Well politically it matters a great deal. The key issue in British politics at the moment is how to deal with the deficit. Labour's argument is that the Coalition has cut the deficit in half, pushing the economy into a double dip recession. If that were true, you would expect all sectors of the economy to be affected.
If instead most of the economy has been growing by about 2 per cent a year but two sectors - financial services and North Sea oil and gas - have been experiencing particular problems, that tells a very different story.
There's still no room for complacency - problems with financial services in particular spill over into the rest of the economy because it means other businesses find it hard to obtain credit - but this is a statistic that deserves wider circulation.