With a 50 percent haircut recently given on the Greek sovereign-debt question, investors are increasingly asking what the real risk of sovereign debt is. It would appear that investors underpriced the risk inherent in sovereign debt, especially that of Europe’s periphery. One might even go so far as to say that investors made foolish choices in the past and are now getting their just deserts.
Such statements require an assessment of what the specific risk is of holding sovereign debt, and how specific European institutions affected these risk factors.
Debt is in almost all cases collateralized by some asset. A mortgage is backed by the value of the house that it is borrowed against. Student loans are backed against the future earnings ability of the student (or their parents’ income and assets if cosigned). In almost all cases debt is collateralized by the asset that it is used to purchase.
Sovereign debt is slightly different, as no clear asset stands ready to serve as collateral. Instead, borrowing is backed by the future taxing capacity of the state. When investors purchase sovereign debt, they do so knowing that if their plans turn out wrong they will not be receiving some portion of that state’s assets as the consolation prize. They purchase the bond knowing that the ability to repay is conditioned by the future economic health of the country, and also by its future taxing power. As there is a general negative relationship between tax rates and economic health there is an upper bound on how much tax revenue can be raised in the future to pay off debts incurred today