Adumbration

Taleb makes the point that debt makes us fragile - the more the worse, and it it not difficult to understand;  the more of ones income must be spent on debt servicing, the less margin remains if there is an earning disruption.  

The Black Swans reference is a good historical citation to express the uncertainty inherent in predicting human behavior and their economic interactions.  I've done some work in statistics over the years, and know enough that normal distributions do not apply in all circumstances.  The long distribution tails that describe economic activity mean people most likely are also underestimating the chances they will experience such an earnings disruption.

Of course this applies for persons and households, as well as nation states.  I don't think our political leaders recognize this problem.  Taleb was also recently interviewed on Planet Money.

Black Swans, Fragility, and Mistakes (5/3/2010) - Nassim Taleb, author of The Black Swan and Fooled by Randomness, talks about his latest thoughts on robustness, fragility, debt, insurance, uncertainty, exercise, moral hazard, knowledge, and the challenges of fame and fortune