Alan Greenspan, that grandmaster of good timing, last week described the current financial crisis as “probably a once-in-a-century event”. The Great Depression began less than 80 years ago but, then again, we are in a different century. Whether or not this will be the worst such upheaval the world has to face between now and 2099, the fact that nothing as bad as the Depression occurred between the 1930s and now is in itself remarkable.