What is certainly clear is that again and again, countries, banks, individuals, and firms take on excessive debt in good times without enough awareness of the risks that will follow when the inevitable recession hits. Many players in the global financial system often dig a debt hole far larger than they can reasonably expect to escape from, most famously the United States and its financial system of the late 2000s.  Government and government-guaranteed debt (which, due to deposit insurance, often implicitly includes bank debt) is certainly the most problematic, for it can accumulate massively and for long periods without being put in check by markets, especially where regulation prevents them from effectively doing so.  Although private debt certainly plays a key role in many crisis, government debt is far more often the unifying problem across the wide range of financial crisis we examine. As we stated earlier, the fact that basic data on domestic debt are so opaque and difficult to obtain is proof that governments will go to great lengths to hide their books when things are going wrong, just as financial institutions have done in the contemporary financial crisis.

From This Time is Different- Eight Centuries of Financial Folly by Carmen M. Reinhart & Kenneth S. Rogoff

HKO Comment- financial regulatory reforms after the Great Depression centered on greater transparency and separating basic banking needs from larger speculation.  This was largely undone by changes under Clinton reducing transparency for derivatives and the final collapse of the wall between banking and investment speculation.  What the authors suggest is needed after the recent crisis is a an extension of the transparency to government debt and government sponsored enterprises such as Fannie Mae.