Answer;
The relationship between unemployment and inflation would eventually stop following the Phillips curve.
Milton Friedman and Edmund phelps in the late 1960s predicted that the relationship between unemployment and inflation would eventually stop following the Phillips curve.
Step-by-step explanation;
Milton and Phelps criticized the idea of a permanent inflation- unemployment trade-off in the mid-1960s on the ground that the behavior of inflation expectations, themselves endogenous to the structure of the economy, would render any such trade-off temporary.