Plagiarism is in vogue, but is it efficient? William Swanson, chief executive of Raytheon, has been censured by his own board after his free booklet, Unwritten Rules of Management, turned out to overlap with W.J. King’s 1944 work, The Unwritten Rules of Engineering. Kaavya Viswanathan, the young chick-lit sensation studying at Harvard, has made the headlines because her novel has been alleged to plagiarise not one but five other novelists. Her publishers, Little, Brown (who also publish my book), have withdrawn the novel. Alas for the plagiarisers: they are being punished for victimless crimes.

Far more sensible, at least to an economist, is the treatment of the novelist Dan Brown. Mr Brown is not a plagiariser, merely a judicious borrower. His novel, The Da Vinci Code, owes an intellectual debt to an earlier work of non-fiction, The Holy Blood and the Holy Grail. But in a famous ruling last month, a British judge, Mr Justice Smith, ruled that this was the only thing Mr Brown owed, because The Da Vinci Code did not infringe copyright.