Actually, based on the empirical evidence, the question as to how much value the ratings agencies actually provide is highly pertinent. The debacle with asset-backed/mortgage-backed securities is, sadly, not the exception. For example, in their seminal study on banking crises and currency crises, Carmen Reinhart and Kenneth Rogoff found that the Institutional Investor and Moody's sovereign ratings did worst in providing early warning of banking crises and currency crashes. For the former crises, real exchange rates and real housing prices did best (that the U.S. financial crisis erupted in the wake of the bursting of the nation's housing bubble and what had been a sustained decline in the value of the U.S. dollar that began paring the rush of capital inflows that had been occurring during the run-up of the housing bubble is par for the course). The latter were best predicted by a combination of real exchange rate trends, banking crises, magnitude of current account deficits. When it came to sovereign debt crises, again the ratings agencies were typically far behind the curve, often caught by "surprise" i.e., ratings downgrades followed the onset of the Asian financial crisis and Greece's debt was downgraded to junk status only after Greece was in the throes of a debt crisis.