Education is crucial: recent research shows that those who earn the basic school-leaving certificate are six times less likely to commit a crime than those who do not.

ECONOMIST: Crime in South Africa

Widad, a 25-year-old secretary of Algerian origin, notes that when she was a schoolchild in Les Yvelines, in the Paris suburbs, four-fifths of her class were North African and only a handful went on to study for the baccalaureate, the school-leaving certificate that is the essential passport to a university or a reasonable job.

ECONOMIST: France's Muslims