The article discusses simple rules that central banks can use to make decisions about interest rates. These rules were developed in the 1970s and 1980s and have been shown to work well with different models. Simple rules are often more reliable than fully optimal rules. They can also be adjusted to account for errors and expectations. In the real world, economies have performed better when central banks followed these simple rules. The recent financial crisis has led to more research on how to handle asset bubbles and low interest rates. Moving forward, there is a need for more research on international monetary issues and the effects of deviating from these rules.