At this point (with h/t to ChrisCook) they are the lynch pin of an economy. Pull it and watch the whole edifice collapse.
"Finance is so central and peculiar, so essential, and yet it carries a death threat for the economy," said Jagdish Bhagwati, a professor of economics at Columbia. "What we've seen, once again, is that finance is a very powerful instrument, but one that needs to be intensively watched."
