Sovereign defaults are pretty much of a given. But since this is the stock market board I fail to see the relevance. If they occur in what the rest of the world sees as the Anglosphere of Ireland, the UK, the US, Canada, Australia, New Zealand and to some extent the predominantly non-white English speaking nations too it could be bad. But Ireland did go into insolvency and the spillover to the US was nil. On the other hand if the Latin American, EU or Far East daisy chains take off a flight to safety to here is likely. If the reference is to the real economy then the answer is pretty much the same.