|The only kind of triple dip that matters|
A rather more subtle statistical misuse comes with all the fuss about whether or not the UK was about to enter a triple dip recession. As it happens we didn't - so the Chancellor could make all sorts of positive political noises about how his policies are correct. If we had, then no doubt the Shadow Chancellor would have jumped in yelling that this showed how bad the government's policies are, and how the country was going to the dogs. Yet either interpretation (and getting all excited about it being a triple dip) is another misuse of the statistics.
To respond this way to these tiny quarterly shifts is similar to sitting on a beach trying to decide whether or not the tide is coming in. A wave splashes onto the beach. 'The tide's coming in!' You cry. Then the sea recedes a little in the post-wave lull. 'No, the tide's going out!' Then the next wave arrives. 'The tide's coming in!' And so on. Very soon you would arrive at a triple tide afternoon.
Any data of this kind has both underlying trends and noise, the noise being random movements that do technically have a reason - but the reason is so complex, a messy mix of factors, that you might as well just regard it as chaotic noise and ignore it. Tiny shifts in GDP from quarter to quarter are just such noise. And should politicians or journalists choose to make much of these 'dips' or 'recoveries' (I was pleased to hear the BBC's Stephanie Flanders avoid this trap on the radio the other day) they are either deluded or trying to mislead us.