Tuesday, March 04, 2008

Lies, damned lies and (shown with) statistics

Bishop Hill has decided to have a lot at MPs' expenses and see whether he could analyse, statistically, whether they were on the fiddle.
My hypothesis was this: if MPs are employing lots of staff, their office costs should be inflated too, to reflect all the work done by the staff. I therefore prepared a scatter plot of office costs (columns 3, 7, 7a and 8 on the PDF file) against staffing costs (column 4). Here it is:


I've asked Excel to calculate a linear trendline, which you can see on the graph. And if you were in any doubt as to how good a correlation there is between staff costs and office expenses, the answer is that there is none. Literally. (For those who aren't statisticians, the R2 value of 1E-5 which is to say, near as dammit zero, is the figure which tells you whether there's a correlation or not. A value of near to 1 is a strong correlation. Zero means there is none.)

Which strongly suggests that quite a lot of our elected representatives are on the fiddle.

Colour me utterly unsurprised.

2 comments:

Anonymous said...

Ever thought of doing a Benfield number analysis of this?

its usually a good revealer of made-up numbers

some random stat guy said...

Nice how it almost maps the the UK geography. Not the first time this has been seen either.