What a puzzle! Unravelling why UK Phillips curves were unstable

The UK relationship between nominal wage inflation and the unemployment rate is unstable. Over sub-periods of the last 160 years of turbulent data, Phillips curve slopes range from strongly negative, slightly negative, flat, slightly positive and strongly positive. Our constant-parameter congruent m...

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Bibliographic Details
Main Authors: Castle, J, Hendry, D
Format: Journal article
Language:English
Published: Wiley 2024
Description
Summary:The UK relationship between nominal wage inflation and the unemployment rate is unstable. Over sub-periods of the last 160 years of turbulent data, Phillips curve slopes range from strongly negative, slightly negative, flat, slightly positive and strongly positive. Our constant-parameter congruent model of real wages explains these instabilities, yet also implies a constant negative relationship between nominal wage inflation and the unemployment rate when corrected by its regressors. Disentangling these effects reveals that structural breaks in the real-wage model's variables do not explain the instabilities, which instead occur during sub-periods when some of its explanatory variables are insignificant.