IMO these banking issues, derivatives etc. are more or less not the cause but the symptoms of the problems. We don't have a "market economy", but an economy of different kind of monopoly rights and structures. The money does not circulate in real economy, but in financial assets. It's a kind of georgist-marxist dystopia, where year after year it becomes more difficult to finance a house, public services and new enterprises (investment) with earnings from labour. Japan had a housing bubble, so the real economy shrunk and debtors/creditors got into trouble. When the economy was loaned up and could not take more debt, banks created some kind of "derivatives" to speculate then on existing loans. I don't see how these derivatives could be the problem. They are not at all real economy and have no cost effects on production of wealth.