We call it the Phillips curve because...

because, Bill Phillips.

Here are his opening words:

When the demand for a commodity or service is high relatively to the supply of it we expect the price to rise, the rate of rise being greater the greater the excess demand. Conversely when the demand is low relatively to the supply we expect the price to fall, the rate of fall being greater the greater the deficiency of demand. It seems plausible that this principle should operate as one of the factors determining the rate of change of money wage rates, which are the price of labour services.

It's simple: It's supply and demand. The simplicity makes for a beautiful opening.

But the Phillips curve no longer seems to work.

That's true. And as Bill Phillips said, it seems plausible that supply and demand should operate as one of the factors determining wage rates.

One of the factors. Supply and demand still works. But something else has taken priority and now has more effect even than supply and demand. Something changed. Something changed so that the Phillips curve no longer seems to work.

And we can pinpoint the time of the change, based on when the Phillips curve stopped working. I didn't look into it, but my previous post was about the Phillips curve not working in the 1990s. But it was working in the 1960s and '70s. Was it still working in the 1980s? You can look into that.

So I'm thinking that the changes of the 1980s were the changes that caused Phillips to fail. Just off the top of my head it could have been supply-side economics, which improved conditions for everything on the supply side, everything except the supply of labor.