What's a good definition of Philip's curve?

Question

Define Philip's curve and give an example.

Answer 1

A Phillips curve (note the spelling, it's named after Alban William Phillips, the economist who first proposed it) is a curve showing a trade-off between inflation and unemployment. In the real world, the Phillips curve is only useful if supply shocks don't occur and inflationary expectations don't change. If they do, you need a more complicated model, such as Robert Gordon's triangle model...