Thursday, February 05, 2009

Figures

One of the things that really winds me up is the bad use of statistics. I have pretty much given up reading newspapers, and in particular the free ones because they so often use statistics that are based on supposition and some weird calculation of averages, with those averages often based on surveys that had a somewhat dubious range of questions. For example “which month is your least favourite?” Answer: January. If you were to take a day off sick, which is the most likely day of the week? (You must provide an answer, even if you haven’t been off sick for years). Answer: Er… Monday. By what day of the month have you normally gone into the red? You must give an answer, even if you are always in credit. Answer: Er… 21st. That is then followed by lots of stories based on very ‘scientific’ evidence that Monday 21 January (or whatever date the ‘statistics’ conjure up that year) is the most depressing day of the year.

So the bad weather is the latest thing to have brought out some ‘statistics’. The main one being cited is that the UK economy lost £1.2 billion due to people not turning up to work on Monday. Shall we just consider how they came up with that figure.

First it is based on the belief that one in five people did not go to work. How did they know that? I think even now most organisations couldn’t tell you what percentage of people were in work – and where I work there were far less than four in five people in. In fact I think less than one in five actually made it in. I realise it is meant to be an average, but where did they get the data from – did they phone round all the HR departments who then wandered round their organisations and took a register.

Second, not going to work does not necessarily mean not working. Plenty of people have the ability to work from home. Perhaps they had intended to go into work that day, but that they then didn’t might have partly been because they didn’t need to in order to do some work or people ‘made do’ with what they had.

Third, where does the figure of £1.2 billion come from? Well according to The Telegraph “The Federation of Small Businesses' estimate is based on studies which show that every Bank Holiday costs the UK economy about £6 billion in potential business”. Right so an estimate of how much money is lost on a bank holiday is divided by a total guess of how many people might have not turned up for work. So you divide £6 billion by 5 and you get £1.2 billion. Of course!

Fourth, it makes the assumption that money not spent on Monday will also not be spent another day. Admittedly if you didn’t buy Monday’s newspaper that money is forever ‘lost’, but if you couldn’t buy a sofa or a car or you weekly supermarket shop you would actually presumably just buy it another day. That’s no lost revenue, it’s just deferred.

But now the media keep quoting the £1.2 billion figure and pile the doom and gloom on to the already depressing news they are peddling about the country’s dire financial situation.

There are lies, damned lies and statistics, as they say.

6 comments:

Kahless said...

I was once asked to produce a particular statistic (I dont want to tell the detail.)

Anyway, last year it was quoted in the house of lords by a government spokesperson.

I calculated the statistic on the 'back of a fag packet."

I laughed when I heard it quoted!

So now it will be in Hansard as fact!

Random Reflections said...

Kahless - oh my! Lots of decisions have probably been made on the basis of your made up figure! You weren't responsible for the current financial crisis perchance?

Kahless said...

Nothing to do with finance actually - it was all in a good cause.

Random Reflections said...

Kahless - oh ok, I'll look elsewhere for a culprit.

lemonpillows said...

Well said, Random.

The worst thing I find about statistics is that they get quoted everywhere once I've produced them. And then I realize that the statstics are wrong because I put the wrong search phrase in my database, but by that time it's too late..

But that's just me..

Random Reflections said...

lemonpillows! Good to hear from you. I hope no-one from you work reads this blog. Your secret is safe with me!