The Phillips Curve
There is a trade off between inflation and unemployment in the short run.  (inverse relationship)
Ad increase upward pressure on prices which cause unemployment decrease and inflation to increase. When AD decrease downward pressure on prices which cause unemployment to increase and inflation to decrease.

Since wages are steady inflation changes moves the point on the SRPC if inflation persist and the expected rate of inflation rise and the entire SRPC move upward. Stagflation is where unemployment and inflation simultaneously rises.
If inflation expected drops due to new technology or efficient SRPC will move downward

Occur at the natural rate of unemployment it is represented by a vertical line there is a no trade between inflation and unemployment in the long run.

Because the economy produces at the full employment output level
LRCP will only shift if LRAS shifts analogous
increase in unemployment will shift LRPC =>
Decrease in unemployment will shift LRPC <=
IF the NRU changes the LRPC moves
NRU is frictional, structural, and seasonal

The MISERY INDEX is a combination of inflation
SINGLE DIGIT MISERY IS GOOD