For a simplistic explanation read my comment!
Explanations of the present worldwide financial crisis are not so clear as to the adjustment process. Was has happened is the United States and many other countries have over invested in their respective domestic housing markets. This was made possible by lax lending practices which did not adequately take into account what borrowers could afford throughout their borrowing period.
Obviously, to make the financial equations balance either peoples' incomes have to rise, or they have to pay out so much of their current incomes for their mortgages that they can afford little else, or they have to receive further loans at concessional rates, or they have to rent out part of their homes, or they have to sell their homes.
To mitigate the overall problems, governments have decided that they will help out by making available more money at concessional rates so that more people can hang on to their homes. What happens in reality is that people try to make ends meet by getting better paying jobs, by getting second jobs, by working longer hours, by divorcing and selling their homes, by declaring bankruptcy, etc.
In some communities, banks have allowed people to remain in their homes but become shareholders. This seems like a reasonably good solution since the debt of the bank is no longer a purely bad debt, but an asset of lower yield, i.e. lower profit. The problem is that the banks have sold on their loans to other entities who are not in a position to dictate the terms of shareholding in the housing market. Indeed in buying the 'housing' paper, speculative buyers, which means banks wishing to convey at the time to others they were in the 'profitable' housing market, leveraged themselves into a crisis. But, what if the original lenders were required to buy back all their housing loans that did not perform! At least then there would be some accountability.
The impact of over-investment in the housing market, which is a long term market, is probably over investment in almost every other market, especially the longer term markets, such as vehicles and all what fills new houses, such as furniture. What this means is that the value or prices of the product of these over invested markets will decline. Those that have over invested will probably under invest as a precautionary rule. This means that the recovery out of this period of over investment could take a very considerable period.
Meanwhile governments will try by various means to soften the impact of recession. If they soften too much people will continue to over invest and a correction to sustainable investment will not happen. That is the problem of low interest rates and easy money. It encourages over investment and pushes against correction to sustainable spending and investment.
Perhaps, if governments focused on redirecting the economies towards CO2 saving industries where there is now under investment, we might just be spared the repeat of over investment.
