Percentages and percentage points

[ChocolateMoose]

Mathematical pedantry here:

If 10% of the population is unemployed one year and 15% unemployed the next year, unemployment has increased by 5% - No! It has increased by 5 percentage points. Unemployment has actually increased by 50% as there are 50% more unemployed people than there were.

I'd just like people who write news bulletins to understand that - am I asking too much? Probably.

But I think it matters when you talk about, say, the risk of some cancer increasing by 20%. The risk may still be quite small, but it doesn't sound it.

I hear you...

You have just made me crave chocolate mousse though, damn you.

Given that the size of the working population has probably changed in the period of interest, there probably aren't 50% more unemployed people than there were.

Probably not, but I think that may be taking pedantry to a new level .

There won't be 5% more unemployed people anyway.

The other day they said that something or other had increased by a certain amount over the last 100 years, but failed to mention that the population figure had also doubled in the same period... so actually the percentage had stayed the same!

Likewise, I am incensed when it is announced that such and such health authority has exceeded their budget by a million quid... but with no indication as to whether that is equivalent to three months spending or half of one day.

Headline figures quoted out of context are totally meaningless.

redbindippurs, tis true, but I thought I'd keep it simple.

Lies, damn lies and statistics...