At the Financial Times, Tim Harford explains why (almost) nobody saw the financial collapse of 2008 coming and why economic predictions are usually so lacking:

“Why are forecasts so poor? The chief explanation is that the economy is complicated and we don’t understand it well enough to make forecasts. We don’t even fully understand recent economic history.

Ben Chu, economics editor of The Independent, recently took a look at the UK recession of the 1990s in the light of two decades of data revisions. From the vantage point of 1995, the economy in late 1992 was slightly smaller than the economy in early 1988. But today’s best guess is that the economy of late 1992 was almost 6 per cent larger than in early 1988. The Office for National Statistics has substantially revised its view.

Not only is it difficult to forecast the future, then – forecasting the past isn’t straightforward either. What chance does any prognosticator have?

A second explanation for forecasting’s fallibility is that there is little incentive to do better. The kind of institutional chief economist whose pronouncement makes it into Consensus Forecasts will stick to the middle of the road. Most countries, most of the time, are not in recession, so a safe strategy is never to forecast one. Of course there are the mavericks who receive media attention for making provocative predictions and are lionised when they are right. Their incentives are different but it is unclear that their overall track record is any better.”