Final answer:
In the short run, inflation and unemployment have a negative correlation as illustrated by the Phillips Curve, where usually one falls as the other rises due to expansionary or contractionary monetary policy.
Step-by-step explanation:
In the short run, the relationship between inflation and unemployment can be most accurately described by saying they have a negative correlation. This is represented by the Phillips Curve, which is a model illustrating the inverse relationship between inflation and unemployment. When expansionary monetary policy is implemented, the goal is to reduce unemployment by increasing overall demand in the economy. This action can lead to higher inflation rates as more money chases a limited number of goods. Conversely, contractionary monetary policy aims to reduce inflation by slowing down the economy, which can lead to increased unemployment. Thus, due to these policies and economic mechanisms, one of these variables usually falls when the other rises.