Sometimes it can be a lot easier to spot what needs to be done than to do anything about it. When the Italian conductor Arturo Toscanini started working in the US in the 1930s, he was initially not impressed with his orchestra. A few moments into his first rehearsal, he tapped his baton on his music stand, and in a thick accent said to the orchestra: “Please, play better.”

It's not difficult to identify many areas where investment banks could "play better" to help free themselves from the vicious circle of declining profitability. Few look quite as obvious as the anomalous and outdated duplication of resources and capital across the banks' two biggest businesses - fixed income and equities - which ultimately do the same thing but with different coloured bricks.