Persistence over the very long run.

I am over at Harvard for a few days, giving a talk tomorrow. Nico Voigtländer and I have a bunch of papers on the long-run consequences of the Black Death. Since I have done some other work on Nazi Germany, one day, we wondered if there wasn't a parallel between the two periods worth exploring. As the plague sweeps through Europe, causing unprecedented mortality, people look for causes - and many blame the Jews for poisoning the wells. In many - but not all - towns and cities in Europe, the Jewish population is brutally murdered in 1348-50. We were wondering if there is some logic to the geographical pattern of violence - and in particular, if we can find the same pattern in the 20th century. It turns out that there seems to be a huge degree of persistence - areas where Jews were burned in the 14th century were much more antisemitic in the 20th. Here is the abstract of our paper [download HERE]:

Persecution Perpetuated: The Medieval Origins of Anti-Semitic Violence in Nazi Germany
How persistent are cultural traits? This paper uses data on anti-Semitism in Germany and finds continuity at the local level over more than half a millennium. When the Black Death hit Europe in 1348-50, killing between one third and one half of the population, its cause was unknown. Many contemporaries blamed the Jews. Cities all over Germany witnessed mass killings of their Jewish population. At the same time, numerous Jewish communities were spared these horrors. We use plague pogroms as an indicator for medieval anti-Semitism. Pogroms during the Black Death are a strong and robust predictor of violence against Jews in the 1920s, and of votes for the Nazi Party. In addition, cities that saw medieval anti-Semitic violence also had higher deportation rates for Jews after 1933, were more likely to see synagogues damaged or destroyed in the Night of Broken Glass in 1938, and their inhabitants wrote more anti-Jewish letters to the editor of the Nazi newspaper Der Stürmer.

With this, we are trying to contribute to the burgeoning literature on the long-run persistence of culture. Guiso, Sapienza and Zingales found that Italian cities with a history of independence had higher rates of trust and income even today; Jha shows that Indian cities with a mercantile past show less violence between Hindus and Muslims over a horizon of 300 years. Relative to these papers, we show a) persistence over a much longer horizon b) the survival of a pure cultural trait without obvious economic benefit, especially since Jews largely vanished from Germany after 1500.

*** Jonathan Haskel, whose intellectual judgement I hold in high esteem, actually called our results "the most amazing correlation he has ever seen". The title of his post? "Are the experts wrong?" ;-)