Back in 2009, there was much talk about the shape of the recession - was it a V, W, U or L. A decade on from the first market tremors, it still feels like a very long L.

Among other advances, the 1870s saw rapid growth of railways (especially in the US), steamships and refrigeration. In many ways, it was the first wave of globalisation.  Together, these contributed to sharp drops in agricultural prices in particular.

But the Long Depression lasted over two decades (1873-96). Is it time to revise our scenario planning?