Bill Russell

‘Modern’ theories of the Phillips curve imply that inflation is an integrated, or near integrated’ process. This article explains this implication and why these ‘modern’ theories are logically inconsistent with what is commonly known about the statistical process of inflation.

United States Phillips curves are routinely estimated without accounting for the shifts in mean inflation. As a result, we may expect the standard estimates of Phillips curves to be biased and suffer from auto-regressive conditional heteroscedasticity (ARCH). We demonstrate this is indeed the case. We also demonstrate that once the shifts in mean inflation are accounted for, the ARCH is largely eliminated in the estimated model and the model defining expected rate of inflation in the New Keynesian model plays no significant role in the dynamics of inflation.

The standard approach to modelling the relationship between world and producer prices of coffee does not incorporate the effects of changing government policies and market structures. These changes have led to large structural breaks in the relationship between the prices implying the standard estimates are biased. We model coffee prices in Brazil, Guatemala and India allowing for the structural breaks and show that the liberalisation of coffee markets has benefited producers substantially both in terms of a higher share of the world price of coffee and higher real prices. This suggests that calls to re-regulate coffee markets may be misplaced.