But even the elite AAA rating currently held by Uncle Sam does not imply a zero probability of default for all time.

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So there is zero probability of default.

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"When the probability of default goes to zero, default is guaranteed, " observes Christopher Whalen, managing director of Institutional Risk Analytics.

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The probability that it is useless is close to zero.

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Now Lloyds may be right that these really are the most succulent and prime of loans, where the probability of them going bad really is more or less zero.

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