Germany's statistical agency has announced that the country has about 1.5m fewer people walking about than previously thought.
That's the equivalent of the country losing the population of a city somewhere between the size of Hamburg (1.8m) and Munich (1.4m), or roughly three Dusseldorfs. No small error.
Statisticians do little better at estimating growth. The US is a classic case of this, where GDI prints seems to read more accurately than GDP (but we're still never quite sure which is better). Yesterday saw the first print of GDI for the last quarter of 2012.
A case study in noisy data:Was 2012 Q4 terrible or terrific?GDP: Advance was -0.1%, revised to +0.4%GDI: Initial print +2.6%, now +5.5%!— Justin Wolfers (@justinwolfers) May 30, 2013
A reminder that we should be cautious in our handling of estimates. In the UK, we'll see GDP revised for decades to come, and that has interesting consequences.
If we can't know how well the economy performed, how can we assess the quality of our politicians when it comes to election day?