By Susan Walker

If everyone says that shocks from outside the financial system -- so-called exogenous shocks -- can affect it for better or worse, they must be right.

It just sounds so darned logical, right? Economists believe this trope to be true, mainly because they believe that investors are rational thinkers who re-evaluate their positions after every new bit of relevant information turns up. Beginning to sound slightly impossible? Well, yes. Read more.