In a wide-ranging presentation and moderated discussion, Commonwealth Bank chief financial officer David Craig has taken aim at the increasing demands by regulators for banks to put safety first. Craig, speaking at a Bloomberg event in Sydney yesterday, was quick to make the point that many of his bank's overseas peers were not covering the cost of their capital and so had let investment lapse in important areas such as technology - and he asserted they have fallen behind the Aussie banks.  Referring to the latest tranche of extra capital raised - some A$20 billion this year alone by Australia's major banks - Craig noted that "safety will always come at a cost which has, in part, to be passed on to customers and possibly shareholders." "We are very conservatively capitalised. The Big Four banks in Australia are right at the very top quartile of capitalised banks in the world, but safety comes at a cost," Craig said.  His concern was that Australian banks maintained an average return on equity of 15 per cent for more than just shareholder value.  "Safe consistent returns are important for the economy," he said. "A strong ROE underpins the credit rating of AA and it's important that this rating is maintained by all banks. "Australian banks borrow on behalf of the economy. If we were lower rated that cost would be higher so it is important for efficiency that we maintain our credit ratings," Craig said. "All of our profits that get paid out as dividends are reinvested in the Australian economy." Craig added that this level of ROE in good times makes it easier to raise capital when it's needed in tough times - provided investors are convinced the bank they are funding will return to profitability. He also said that the banking sector needed to be "constructively paranoid" about changes and threats from some of its smaller fintech competitors. He said CBA was keeping a watching brief on their developments - including visits to Silicon Valley - but also observed: "The point is that things really keep moving [in technology] and it's very hard to pick winners early on.""At the same time we have an incredible responsibility to keep everything stable. If our banking system goes down for five minutes it has an enormously disruptive effect on the Australian economy." In Craig's view, the big banks (his included) would be better served working out better ways to use big data. Using the emerging "sharing economy" and a growth in the number of customers with several sources of income, Craig said CBA was working toward a "detailed and intuitive" understanding of its customers' sources of income and their saving and spending patterns. And unsurprisingly he was underwhelmed at the thought of a goods and services tax on financial services (a topic studiously avoided by Treasurer Morrison in his presentation and subsequent Q&A session to open the Bloomberg conference).  "There has been no other country in the world that has been able to work out how to apply GST to financial services," Craig