Despite a recent raft of data pointing to a brighter picture for the British economy, the lack of productivity, or the amount of output produced by a single worker in an hour, has left policy wonks scratching their heads.
The so-called "productivity puzzle" is that while the unemployment rate is falling, and wage growth has finally outpaced inflation, individual workers' output remains disappointing.
And so, the Office of National Statistics (ONS), has crunched data to reveal which areas are the most productive. Unsurprisingly, London leads the way, with its workers 42 per cent more productive than the national average.
The home counties are close contenders, with Berkshire, Buckinghamshire and Oxfordshire hot on its heels. Here average productivity was 21 per cent less than London's, but it was still 21 per cent higher than the national average.
The worse performers were rural economies like West Wales and The Valleys and Cornwall and the Isles of Scilly. This is due to the decline of industries like mining and ship building as well as a lack of connectivity.
London may be a leading light, but Britain's productivity still lags behind some of the world's most advanced economies. This means we're lower than France, Germany and the US by between 27 to 31 per cent. And on average, Britain's productivity is around 17 per cent behind the rest of the G7.