MPC, the Multiplier and Gaps In this lesson, we will put together all of the pieces of the model. Remember, our goal is to reach long run equilibrium. No gaps! Gaps occur when what is actually going on in the economy is different from what it can do at full employment. Think of yourself as a doctor, but instead of working on people you're working on the economy. Sometimes, the patient (the U.S. economy is anemic-not enough CIGX-which causes a recession. Sometimes, the patient (the U.S. economy) is Hyperactive-too much activity-which causes inflation. As the doctor, your training (the AD/AS Model) tells you that certain conditions call for a certain treatment and that other conditions call for other treatments. The AD/AS model helps us to understand the causal relationship between the ailment and the treatment. Note that I refer to a treatment and not a cure. In the next three units, you will see whether the treatment works as the model indicates, whether we are treating only the most immediate symptom such as the headache rather than the underlying sinus infection, and whether the treatment is sometimes worse than the cure