Evidence-basted policy

A prominent economic study, supposedly showing that growth slows down once national debt gets above a certain level, has turned out to be based on a few simple errors.

Carmen Reinhart and Ken Rogoff’s research was quoted approvingly by supporters of austerity around the world, including George Osborne in a major speech in early 2010. Osborne has consistently argued that the government needs to reduce its borrowing and debt or risk all kinds of disaster, and this research gave him a handy few paragraphs of material.

But he won’t now reconsider.

Politicians like us to think – and they probably like to think themselves – that they go for evidence-based policy. This makes them look like wise, careful, well-informed pragmatists.

But, too often, they don’t go for evidence-based policy. What they go for is evidence-basted policy.

Here’s how to do it:

1. Choose your policy.
2. Scour the publications of friendly think-tanks and academics to find evidence that seems to support your policy.
3. If you also find evidence against your policy, cut this off and throw it away.
4. Marinate your policy in the evidence that most complements its taste, and cook as needed, sealing in that delicious evidential flavour.
5. When your policy is ready to serve, it will be all the more appetising.

All the austerity camp have lost this week is one ingredient for their marinade. But this hardly matters to them: that wasn’t the reason they chose this course. They’ll keep serving it, even if it now tastes a little bitterer. A change of evidence doesn’t mean a change of course.