Skip to main content

Numbers in the news

When people ask me about statistics they hear on the news, I suggest two questions they ought to bear in mind, and as a result of which they should employ appropriate scepticism. Those questions are:
  1. What does that mean?
  2. How do they know that?
Let me demonstrate. You hear there has been a 100% increase in a particularly nasty crime over the previous year. That's horrendous. The world is unsafe. We'd better legislate. But hang on. What does that mean? 100% of what? It turns out the previous year there was one instance. This year there were two instances. Stand down the national guard.

Another example to deploy question 2. I heard recently on the news that exports were up by so many percent over the previous year. How do they know that? I have several activities that count as exports. For instance, one of my main publishers is St Martin's Press in New York. As a result of selling them my books, money flows into the UK. This is an export, even if a physical object doesn't get popped in the post. But will that show up in their statistics? I can't see how. There must be many thousands of small businesses, exporting physical goods for internet sales, for example, where again I can't see how those sales will get into those export figures. The fact is, though they don't admit it, that this must be a guess - and not a very good one.

Comments

  1. A few months ago, the BBC News site promised to explain these sort of percentage figures they use.

    For example:
    Eating bacon increases the risk of some cancer by 20%

    Sounds bad?
    Not until you work out the figures properly. (I don't have the exact figures to hand, but it's something like...)

    If 5 people per 100 get this cancer, then if everyone ate bacon every day, then the figure would be 6 people per 100.

    So, the 20% is somewhat misleading.

    However, since the BBC News site made that promise, I've yet to see a single additional explanation...

    ReplyDelete

Post a Comment

Popular posts from this blog

Why I hate opera

If I'm honest, the title of this post is an exaggeration to make a point. I don't really hate opera. There are a couple of operas - notably Monteverdi's Incoranazione di Poppea and Purcell's Dido & Aeneas - that I quite like. But what I do find truly sickening is the reverence with which opera is treated, as if it were some particularly great art form. Nowhere was this more obvious than in ITV's 2010 gut-wrenchingly awful series Pop Star to Opera Star , where the likes of Alan Tichmarsh treated the real opera singers as if they were fragile pieces on Antiques Roadshow, and the music as if it were a gift of the gods. In my opinion - and I know not everyone agrees - opera is: Mediocre music Melodramatic plots Amateurishly hammy acting A forced and unpleasant singing style Ridiculously over-supported by public funds I won't even bother to go into any detail on the plots and the acting - this is just self-evident. But the other aspects need some exp...

Murder by Candlelight - Ed. Cecily Gayford ***

Nothing seems to suit Christmas reading better than either ghost stories or Christmas-set novels. For some this means a fluffy romance in the snow, but for those of us with darker preferences, it's hard to beat a good Christmas murder. An annual event for me over the last few years has been getting the excellent series of classic murderous Christmas short stories pulled together by Cecily Gayford, starting with the 2016 Murder under the Christmas Tree . This featured seasonal output from the likes of Margery Allingham, Arthur Conan Doyle, Ellis Peters and Dorothy L. Sayers, laced with a few more modern authors such as Ian Rankin and Val McDermid, in some shiny Christmassy twisty tales. I actually thought while purchasing this year's addition 'Surely she is going to run out of classic stories soon' - and sadly, to a degree, Gayford has. The first half of Murder by Candlelight is up to the usual standard with some good seasonal tales from the likes of Catherine Aird, Car...

Is 5x3 the same as 3x5?

The Internet has gone mildly bonkers over a child in America who was marked down in a test because when asked to work out 5x3 by repeated addition he/she used 5+5+5 instead of 3+3+3+3+3. Those who support the teacher say that 5x3 means 'five lots of 3' where the complainants say that 'times' is commutative (reversible) so the distinction is meaningless as 5x3 and 3x5 are indistinguishable. It's certainly true that not all mathematical operations are commutative. I think we are all comfortable that 5-3 is not the same as 3-5.  However. This not true of multiplication (of numbers). And so if there is to be any distinction, it has to be in the use of English to interpret the 'x' sign. Unfortunately, even here there is no logical way of coming up with a definitive answer. I suspect most primary school teachers would expands 'times' as 'lots of' as mentioned above. So we get 5 x 3 as '5 lots of 3'. Unfortunately that only wor...