I have been reading Joseph Conrad’s Typhoon, the least sentimental of Christmas stories. It describes how Captain MacWhirr and the crew of the Nan-Shan spent the day saving the ship from a storm in the South China Sea. The typhoon broke open the camphor chests belonging to the 200 Chinese labourers on board, leaving a pile of anonymous silver dollars.

The resulting problem has become known as Captain MacWhirr’s dilemma. How can you distribute a prize among a group when only the individuals concerned know the size of their contributions and must be expected to exaggerate them? Capt MacWhirr concluded that the only possible solution was to divide the money equally.