That being said, current estimates still appear to point to a flatter slope of the Phillips curve than in the past, which could be interpreted as an indication that the relationship between economic slack and inflation has weakened.
This weakening might be partly the result of a mismeasurement of slack (because of structural changes in the labour market) or an unstable relationship between slack and inflation over time. At the same time, this effect could also result from discrete parallel shifts in the Phillips curve.