Banks may have to raise extra £50bn under emerging 'Basel IV' At the weekend, Anthony Browne, chief executive of the British Bankers' Association (BBA), said: "Banks could be incentivised to chase the higher risk and higher return businesses instead of giving families with good credit histories affordable mortgages." The BBA said that, while other major countries appeared to require higher leverage ratios for their banks, when other factors were taken into account their rules were not as tough as they appeared. For instance, under US rules, a bank holding exactly the same amount of capital as a European bank applying the Basel III standards would have a leverage ratio of 5.34pc, compared with 3.08pc for the European bank, according to the BBA's calculations. The attraction of the leverage ratio is that it is far simpler to measure than other capital ratios which are based on the risk-weighted assets reported by banks. Lenders have been found to apply vastly different risk weights when measuring the riskiness of identical assets and the use of internal risk models has been blamed in part for helping create the financial crisis. Regulators remain worried that banks remain vulnerable to a new crash and that they have learned little from the last crisis.