There is nothing more profitable for the banks than confusion about what they do. As long as they keep talking about acronyms no one has heard of and financial theories that no one understands, they can continue the enormously profitable business of borrowing money at low rates and lending it at high rates. This year alone the result of this strategy will generate after tax profits worth more than $22 billion, more than $1000 for every man woman and child in the country. The problem for the banks, however, is that they are finally being asked some hard questions about their simple strategy, and the answers haven’t been pretty. The hardest, and from the banks’ point of view the most heretical, question is the one that Steven Munchenberg from the Australian Bankers Association fumbled so badly in today’s Sydney Morning Herald: that is, why do banks even need to increase mortgage interest rates in line with movements in official interest rates?