Today, we meet Professor Hans-Joachim Voth to discuss some of his work on the economic forces around religious and political epochs characterised by extremism. We begin by reviewing the long term economic effects of the Spanish Inquisition and consider the historical roots of anti-semitism in explaining Nazi support centuries later. Finally, we look at how "social capital" may have negative effects in garnering support for extremist movements and look at the effects of road building on political votes for the Nazi party.