The four biggest US banks have just received the first instalment of benefits that corporate America will reap from lower federal taxes. According to The Wall Street Journal's analysis, the extra haul for JPMorgan Chase & Co, Wells Fargo, Citigroup and Bank of America is more than US$2.5 billion. That's only a modest-size chunk of the banks' total first-quarter earnings - less than 10 per cent of their combined net income - but it accounts for a major chunk of their year-on-year earnings growth. In fact, Wells Fargo's earnings would have declined, and Citigroup would have lost most of its net-income growth from a year ago without big cuts to their effective tax rates. Investors were unimpressed: Wells Fargo shares have fallen 4 per cent, JPMorgan's have slipped 2.8 per cent and Citigroup's have lost 3.3 per cent. In its latest Fiscal Monitor report, the IMF has warned of the rise in risk related to sharp rises in global debt, particularly government debt and particularly Chinese debt.