Interpreting Financial Statements - a Global Focus: NAB Saw Its

Interpreting financial statements - a global focus: NAB saw its share price fall by more than 12% after it announced provisions for a potential loss of $830 million on debt-related investments due to the global credit crisis and fall in the US housing market. The $830 million was in addition to the $181 million NAB had already provided for to cover risky investments. NAB chief executive John Stewart said that the losses were likely due to rapidly increasing mortgage defaults, stating, 'Unfortunately the behaviour of the housing market in the US leads us to believe that the worst case scenario may not be too far away from the most likely scenario'. Numbers indicating US home sales have fallen to a 10-year low and Ford booking a record loss of $US9.1 billion in its latest quarterly results sparked a steep decline on the US share market.
Required:
(a) Viewing the most recent annual report available on its website (www.nab.com.au), identify how NAB determines impaired receivables.
(b) Compare NAB's policy with Barclays'. (You can access Barclays' most recent annual report via www.barclays.com.)