"If people learn to use equation (4) to predict inflation, then expected inflation (on the right-hand side) should be set to whatever they forecast for actual inflation (on the left-hand side). But equation (4) says that if actual and expected inflation are equal, then unemployment must be at the nat"
"So long as we are making predictions based on information available to the public, then the values we use for π^e should be the same as the values the model predicts for π."