How do you make a banker happier and more productive? Pay them a bigger bonus? Wrong. The right thing to do could be to make them give to charity, and make them give big.

On Monday, FN reported that French bank BNP Paribas was offering its UK staff the option of paying a proportion of their bonus to a designated charity (the bank's Rescue and Recover fund, which offers aid victims of humanitarian disasters) and have that donation matched by the bank from €100 to €500,000.