The change that we are facing now is not essentially about investment banks, mortgage lenders, or homebuyers. Rather, it reflects the transition of the global economy to an era in which the US cannot be the only hub at the center of the wheel.
C. Fred Bergsten and Arvind Subramanian, in today's Washington Post, help to explain how this process underlies the more obvious signs of crisis.
Beyond the short term, countries will need to develop a cooperative framework to prevent and resolve such crises, most urgently within Europe. There is inherent tension as finance becomes global but its regulation remains national. The current crisis originated in the United States but was importantly affected by massive savings surpluses in some countries and the resulting surfeit of liquidity, which drove down interest rates and encouraged irresponsible lending here. Those international imbalances were in turn partly caused by misaligned exchange rates. Global oversight of both financial regulation and currencies can no longer be neglected.
One way to understand this is that China, most importantly, has artificially increased its capital reserves by preventing its currency from appreciating to its correct market value. China sells more exports than it otherwise would, and buys fewer imports than it otherwise would. Ultimately, the Chinese money does make it back to the US, but in the form of payments for Treasury Bills (This is due to a Chinese concern about inflation as well as a concern that excess capital would lead to social unrest and/or uncontrollable wealth flows that could weaken Communist Party control.).
Simply put, it seems to me that the net consequence is that cash comes to the US Treasury rather than to, among others, US producers. The cash in the Treasury was then ultimately lent out at low interest rates, creating investment opportunities in a society in which wages were not appreciated significantly (because of, among other reasons, the fact that American products were not easily sold to countries that have maintained a high exchange rate of local currency to dollars).
The predicament in which consumers cannot afford appreciating assets in reminiscent of the pre-Depression years in which consumers could not afford proliferating production. The similar increase in consumer credit is an unsurprising result.
Essentially, a change in global financial architecture is needed, not only for the reasons mentioned by the authors, above, but also so that the US can benefit most fully from concentrating on the development of its human capital, the long-term sine qua non for economic growth and political stability.
Concerns about political stability should not be minimized. The inherent tensions between communities constituting a democratic society are generously lubricated by growing wealth. The sense of chaos that can percolate through a society in the absence of such a scenario lends itself to exploitation by authoritarian-minded regimes. I do not think that the US is on the brink of such a scenario but the 20th century taught us well that farflung events can have a dramatic impact on our society.