Michael Wildt and Marc Buggeln, Humboldt University, Berlin.
At what point did people start to ostracize their neighbors economically because they thought they were of a different ethnic group? Who decided who was to be excluded? Where did the fault-lines open? Where did the boundaries lie? How were they defined – by law, or by common practice? How much extra time and money were people prepared to spend in order to do ostracize their neighbors? And what did that mean for the economy – and society – as such?