The recent refugee crisis has fuelled discussions about policies restricting immigration. This column quantifies the extent to which asylum policies affect emigration by analysing the migration decisions of German Jewish refugees in the 1930s. Policies have large effects on migration as the effects are multiplied through peers who influence each other in the decision to emigrate. Removing work restrictions for refugees in the recipient countries after the Nuremberg Laws in 1935 would have led to a 28% increase in Jewish emigration out of Germany.