One big question about the analytical underpinnings of the stress tests: The assumed correlation between unemployment and credit card write-offs. There's no doubt there's a strong relationship. The issue is whether the slope of the line is a bit steeper in this recession, that is, will the normal assumptions about layoffs and charge-offs understate the likely losses.

The New York Times suggests that more people (compared  to previous downturns, anyway) will keep their jobs but default on their debts. The bank stress test results "suggested that the nation's 19 biggest banks could expect nearly $82.4 billion in credit card losses by the end of 2010" in the worst case. But if unemployment heads north of 10 percent, losses could "far exceed that level." The government's projection did no include some ancillary costs, notably losses associated with credit-card backed securities.

For more:
- here's the article

Related Article:
Banks scrambling to get grip on card risks