Autocracies have been disappearing across the globe over the past two decades. Yet the collapse of dictatorships has frequently led not to democracy, but to chaos (see charts). Thomas Hobbes, author of Leviathan, thought the absence of any government worse than the presence of a bad one. Life, he declared, is then “nasty, brutish and short”. Government by psychopath may well be still worse than anarchy. But run-of-the-mill autocracy is not.

What political fate, then, is likely to befall Iraq, Russia, Lebanon, Ukraine, Chile, Tanzania or any of the multitude of countries that have moved towards democracy in recent decades? To answer these questions, we need to explain not only why democracy emerges, but what determines its subsequent stability.