Is it governments that control the economy? Banks, perhaps? Or maybe even the people? Nope, in fact, it's rating agencies—and the there are three in the US that practically control the entire economy.

These agencies rate everything—organizations, companies, currencies—and gives it a score. The knock-on effect is that bad ratings—which can sometime be fairly arbitrary—have a massive effect on national economies. In this talk, Annette Heuser explains why rating agencies are a problem—and how it can change. [TED]