
Economists working on macroeconomic policy – things like taxes and spending, interest rates and border controls on flows of trade and money – often refer to a set of key relationships governments can influence. In the textbooks, each of those relationships is drawn as a curve in a graph.
First is the IS (“investment–saving”) curve. This says that if everything else stays the same, the Reserve Bank can increase economic output and employment by lowering the interest rate. Or it can cause a recession by raising the interest rate. (For simplicity’s sake, the curves here are depicted as straight lines.)