Do economic factors influence exchange rates? Or does market sentiment play a bigger role? Are short-run exchange rates predictable? Greg Hopper reviews exchange-rate economics, focusing on what is predictable and what isn't. He also examines the practical implications of exchange-rate theories...

On an international level, countries often engage in vigorous debate about which type of exchange-rate system to follow – fixed or flexible? A question central to that debate is: Does one particular exchange-rate system promote a more stable economic environment?