The Office for National Statistics uses the changing prices of a basket of staple goods to help it calculate inflation. But - the Guardian reports - the private bank Coutts feels the items the ONS tracks don't reflect reality for the very wealthy. It's created its own more upmarket shopping list. Taking into account trends such as recent hikes in the price of oysters, as Chinese consumers develop a taste for them, it's found that the rate of inflation for the super-rich is 5.9 % - more than twice the rate experienced by the rest of us.