From today's Financial Times:
"The expression “good servants and bad masters” has been applied to so many things: technology, government officials, mathematical models and much else. Today I want to apply it to the financial markets. It goes without saying that we need mechanisms for channelling surplus savings into physical investment, for a second-hand market in titles to ownership, for shifting personal spending over time, for saving for old age, and much else. But when these markets become overextended to the point of determining the fate of governments it is time to call a halt. This is especially the case when the funds in question arise from artificially created money rushing across frontiers. To change the metaphor, it is the tail wagging the dog."