CBA chief executive Ian Narev said the board spent an hour last week examining capital levels in the meeting, at which chief financial officer David Craig took the board through half a dozen scenarios involving a collapse in the economy.

"That's how we work out how much capital we think we should have," Mr Narev said. "We have said on many occasions that we believe we hold sufficient capital, and we continue to believe we hold sufficient capital."

The financial system inquiry is closely examining bank capital levels, with most banking analysts expecting chairman David Murray to call for higher equity to reduce bank leverage and provide a larger buffer against future shocks.

The big bank chief executives have told Mr Murray his final report, due with the Treasurer next month, should not delve into the detail of capital settings, which is a matter for banks and regulators. Mr Narev said he was satisfied with the inquiry's levels of consultation. "We felt like we were heard. We will see afterwards whether we were also convincing," he told the American Chamber of Commerce in Australia.

Responding to Reserve Bank assistant governor Guy Debelle's warning on Tuesday that markets could suffer violent disruptions when interest rates rise, a result of low volatility, Mr Narev said "there is a very wide range of views still on how that will play out in markets in the near term and medium term. Nobody knows what the answer is."

But it was entirely appropriate for Mr Debelle to make such warnings, to "make sure the economy doesn't get exuberant and doesn't get complacent and understands its risks ... I think the fact he has given another wake-up call for all of us who act in markets not to get complacent is very appropriate."

Mr Narev argued that while the multifarious risks to the global economy – which include the European and Chinese economies, geopolitical and climate risk, and the direction of US Federal Reserve on interest rates – were serious and could "make life quite difficult here for a period", business leaders should balance these with numerous positives about the economy.

These include trend GDP growth, high levels of household savings, strong corporate balance sheets and credit quality, and the focus in the federal government on reining in commonwealth debt and the Reserve Bank's management of monetary policy, which Mr Narev said had been done "exceptionally well".

"It is very important that while being cognisant of the risks, avoiding complacency and as leaders of business being very prepared for what of some of those factors could do to our businesses and to the economy, we are also prepared to take some strength from the very solid foundations that we have here," he said.

"If you want to prepare a strong economy for the future, this is a pretty good place to start."

He also emphasised the importance of the B20's recommendations to the G20 on infrastructure, including the need to identify priority projects and properly allocate risk between the private and public sectors. He praised the NSW state government led by Premier Mike Baird for getting this right.

Reflecting on the ways in which the financial crisis had changed banking, Mr Narev said many banks had forgotten they are "enablers" of business and "are not masters of the universe".

So it was no surprise global regulators are ramping up oversight of banks, which also reflected community demands for banks to be safer and more responsible.

"We can have arguments about whether aspects of the regulatory response to that public mood might have been excessive, but in our minds that public mood is undeniable, and therefore it is a fact of doing business that for some period of time – and maybe an indeterminate period of time – the investment requirements for regulatory purposes are going to be very high.

"Yes, that does crowd out some other investment, but that is a reality of being a financial institution today and that is something you are going to have to be prepared to live with."

Mr Narev also addressed CBA's review of financial advice. Information packs had been sent to 3067 of the 4200 people who had registered for a review of their advice; all would receive information within 10 days, he said.

In reviewing the claims, CBA would be guided by the principle that "whereever we have done wrong, we are going to put it right."

"Not actually because we're worried about what people might write or what people are going to say, because there are always going to be individuals who take pot shots at any institution," Mr Narev said.

"We are worried about it because we let down customers, and by letting [customers] down you undermine the trust that is so critical to a financial institution."

The bank had seen how its actions "can still tarnish the reputation of an institution" and this was being taken "extremely seriously ... because we let down customers, and letting down customers undermines the trust that is so critical to a financial institution".

"That extends beyond financial advice and basic banking to privacy, use of information and other new elements of trust associated with the digital age."