摘要:The statistical properties of inflation and, in particular, its degree of
persistence and stability over time is a subject of intense debate, and no
consensus has been achieved yet. The goal of this paper is to analyze this
controversy using a general approach, with the aim of providing a plausible
explanation for the existing contradictory results. We consider the inflation
rates of twenty-one OECD countries which are modeled as fractionally integrated
(FI) processes. First, we show analytically that FI can appear in inflation
rates after aggregating individual prices from firms that face different costs
of adjusting their prices. Then, we provide robust empirical evidence supporting
the FI hypothesis using both classical and Bayesian techniques. Next, we
estimate impulse response functions and other scalar measures of persistence,
achieving an accurate picture of this property and its variation across
countries. It is shown that the application of some popular tools for measuring
persistence, such as the sum of the AR coefficients, could lead to erroneous
conclusions if fractional integration is present. Finally, we explore the
existence of changes in inflation inertia using a novel approach. We conclude
that the persistence of inflation is very high (although nonpermanent) in most
postindustrial countries and that it has remained basically unchanged over the
last four decades.